1.Biological Control... 2.Blob... 3.Botanical Latin... 4.Broad genetic base... 5.Broad leafed... 6.Built-up Coastal... 7.
Climate and Microclimate... 8.Cloud Pruned... 9.Co-dependent... 10.Coniferous... 11.Conservatory Plants... 12.Coppice... 13.Creative Maintenance... 14.Crown raised or lifted... 15.Deciduous... 16.Dicot... 17.Drought tolerant... 18. Dwarf... 19.Endemic... 20.Epicormic growth... 21.Epiphyte / Epiphytic... 22.Evergreen... 23.Fastigiate... 24.Feathered... 25.Frequently Asked Questions... 26.Frost Pocket... 27.Genus... 28.Glaucous... 29.Gherkin... 30.Habit... 31.Hardy... 32.Haircut... 33.Half Standard... 34.Hedge... 35.Indoor/House Plants... 36.Indumentum... 37.Karikomi... 38. Microclimate... 39.Micropropagation... 40. Monocot... 41. Mound... 42. Multi stemmed... 43. Niwaki... 44. Pathogen... 45. Pests and Diseases... 46.Posh... 47. Pot Plants... 48. Prostrate... 49.Provenance... 50.Relic... 51.Shrub... 52. Species... 53.Standard... 54. Stool...55. Suckers... 56.Taxonomy... 57.Tender... 58.Topiary... 59. Tree... 60.Tropism... 61.Twmp... 62. Undulation... 63.Urban Heat Island... 64.Wrapping for Winter
1.Biological Control : This is the science of introducing various bugs and bacteria to interfere with the life cycle (i.e. kill) various other bugs and bacteria that imperil the health of plants. It's become big business as it's used in the cultivation of many salad, veg and fruit crops and is now controlled by the multi-national pharmaceutical firms. It's clever, it works, it's extremely interesting and generally a safer and nicer option than using chemical agents. In the garden, I'd say it's unnecessary (your garden is full of natural biological control - ladybirds, lacewings etc etc) so this is really only of interest if you're growing plants in a conservatory or a greenhouse. Actually, it's more than of interest - it's vital. Rather than listing all the symptoms, diagnoses and cures here, I will get some up to date websites to link to to help. First I need to speak to Karen, our P & D person (pests and diseases). You will need a good quality magnifying glass and you will need to prepare yourself to become fascinated. Some of the processes are gruesome in the extreme.
2.Blob : Noun. A word that's gone from being a dismissive pejorative to a highly desirable horticultural commodity. It describes the doughnut shape so popular with oriental topiarists and now becoming popular over here. It's used - you may have gathered by now - in the context of clipped plants. It's distinct from the traditional European 'ball' shape; almost flat topped, descending to almost perpendicular sides, just tucked in a tiny bit at the bottom. If you grow lots of blobs together, they could become contiguous (touching). The next evolution from 'blob' to 'contiguous blob' would be an 'undulation'. We love blobs in all their manifestations. What we don't like (except on very rare occasions) are gherkins. See 'gherkin' below.
3.Botanical Latin : A form of Latin, that's largely made up by taxonomists (see 'Taxonomy' below) that's used to describe plants - universally, throughout the world, by everyone. Most of our customers find it annoying but without it, mighty confusion would reign. If everyone used the common names to describe plants from around the world, it would be hell. Ask if we grow 'Elephants ears', 'Sacred Bamboo', 'The Japanese Upsidedown Plant', 'Pohutakawa' or 'The Wonky Tree' and we're unlikely to be able to help. Ask us if we grow Bergenia cordifolia, Nandina domestica, Sciadopitys verticillata, Metrosideros tomentosa or Salix matsudana 'Tortuosa' and - believe it or not, we (and every other grower in the whole world - apart from Americans who hate Latin names) will know exactly what you're talking about. Sometimes, plants are named after a person or a place and are Latinised (e.g. 'Father Delavay' becomes 'delavayi' or 'The Chatham Islands' become 'chathamica') and often the Latin ending '-oides' is used to denote something is 'similar to' something else (e.g. 'jasminoides' means 'similar to' 'Jasmine'). Think of 'cube' and 'cuboid', 'ellipse and 'ellipsoid', 'rhombus' and 'rhomboid' etc. Same thing.
I'm not an expert on Botanical Latin so I proceed with caution but Latin names often help by describing the leaf or flower. There's not a huge vocabulary used so it's not that difficult but here are a few examples : we grow a tree called Lyonothamnus floribundus aspenifolia. Not sure about Lyonothamnus (probably named after someone called Lyon as in Corner House), 'floribundus' means 'flowers a lot' and 'asplenifolius' means it has a 'leaf' ('folius') like a 'fern' ('aspleni-' refers to the Asplenium fern). Another good one is Hebe parvilflora angustifolia. Hebe means it's a Hebe (Greek Goddess?), 'parviflora' means 'small flowers' ('parvi' - 'small', 'flora' - 'flowers') and 'angustifolia' means narrow leaf ('angusti' - 'narrow, 'folia' - 'leaves'). "Can I have a Hebe parvilflora angustifolia?" might be a mouthful but it's got to be better than "Can I have 'The Plant (possibly) named after a Greek Goddess with small flowers and narrow leaves? please, thank you very much". We have a book in our library called 'Botanical Latin' that may or may not get put on your present list but here, I hope, I have given a taste of the subject and its importance. Three cheers for the Taxonomists - wherever they are. No idea. Gary Larson cartoons come to mind.
4.Broad genetic base : Noun. Botanical jargon. I think it means that a plant is genetically unstable. In other words - sow 100 seeds from the same plant and from the emerging seedlings, expect there to be many different forms of the same plant - if it has 'A broad genetic base'. New Zealand Flax (Phormium tenax) is one of the best examples of this phenomenon which is why there's such a confusing array of different plants with different coloured leaves and different names. We will always clone a plant whenever we can (by cuttings, micropropagation or division) so we know what we're getting. Some plants we can't propagate by these methods and have to use seed. If it comes 'true from seed' (meaning it has a 'narrow genetic base') that's fine because you pretty much know what you're getting. Acacia dealbata and Acacia pravissima are two plants we propagate from seed for this reason - they come true from seed. An example of a plant that has a broad genetic base that we can only grow from seed (because no other method works but we really like the tree) is Maytenus boaria from South America. It just means you never quite know what you're getting - a horticultural adventure. This phenomenon is a fundamental element of evolutionary theory.
5.Broad leafed : Adjective. This refers to all woody plants - whether evergreen or deciduous - that are not coniferous (pines, spruces, cypress etc etc)
6.Built-up Coastal : An expression we use to denote geographical location - the position of a garden. The combination of being near the sea but in a built up area means your garden will be much warmer in the winter than in adjacent rural areas inland. The nearer the sea you are, the milder the winters and the closer to the centre of a large built up area you are, the warmer it will be. Meteorologists call the effect on microclimate on built up areas The Heat Island Effect.
7.Climate and Microclimate : Noun. xxxxxx
8.Cloud Pruned : Adjective. Some people use this to refer to Niwaki (like big Bonsai) but we tend to use it to refer to lumpy bumpy undulations or what the Japanese would call karikomi. The Welsh twmp is also related. See the rest of this glossary for further thoughts on some of these words.
9.Co-dependent : Adjective. What a lovely big subject this is and how little I know about it and how much more I wish I knew. Deep within the evolutionary process different species of plants and animals have evolved together and in many cases become dependent upon each other - they can't actually survive independently; hence the expression Co-dependent species. In the case of human beings, it's now well understood that we cannot survive without the immensely diverse flora (as it's known) that exists in our gut - so much so that it's now thought that our obsession with cleanliness has failed to stimulate our immune systems and has lead to the modern epidemic of immunodeficiency disorders - diabetes for example. But what about plants? I think we have much to learn. For many years we've produced a tree called the Bamboo Leafed Oak (Quercus myrsinifolia) from seed. It's a very beautiful tree and we had to do it BUT they used to struggle in their pots and on the rare occasion that somebody wanted to buy one we'd say (half jokingly) :"We guarantee it'll die, they always do". Often, the customer was so keen to acquire the plant they'd reply "Oh, in that case I'd better have two". It went on like this for many years and then we suddenly realised that all the trees we were producing were growing really well and happily and now they never die and we hear reports of how well they've done. You're probably hoping there's a punch line to this story. Unfortunately not - other than we obviously changed something we did but we don't know what it is. Different compost? Different mulch? I remain convinced that this is a story about co-dependent species - there's some pathogen present which makes life for that tree very tolerable whereas previously it was absent. How we introduced it, God knows. It should be mentioned that there are now mycorrhizal fungi that you can buy and introduce to your roots - either on the nursery or once they're in the ground. We have experimented but remain agnostic. The trouble is that they're endemic - they're everywhere anyway. What we'd like to know is which ones work with which plants. We may never know.
10.Coniferous : Adjective. Literally, it means cone bearing and is a massive sub-division within the plant kingdom. Most are evergreen (a few like Larch, are deciduous), most are resinous (you get covered in sticky stuff when working on them), most are trees (but some are shrubs)Â and they are veryÂ widespread. The ones from high latitudes (particularly in the north hemisphere - Spruce, Hemlock, Fir etc) are conical when young and remain conical.Â Probably something to do with being covered in snow all winter. The ones from lower latitudes are mostly Pines and although conical when young, allÂ become round headed on tall trunks after many years. It's the Pines and some of the in-betweens (Podocarps, Yews etc) that we specialise in here at A.P.
11.Conservatory Plants : When we started the business in 1990, conservatories were all the rage. Everyone wanted one or had one and everyone had been lead to believe that they were great places to grow plants in. Trouble is, they're not. They're hot and dry and breeding grounds for every imaginable bug. A friend once likened it to trying to grow plants in a tandoori oven. Since then, sanity has returned and everyone now accepts that growing plants in conservatories is a challenge. Greenhouses are wetter and better ventilated but still quite a challenge. The average conservatory contains furniture, cushions and magazines and they don't go well with the humid atmosphere that most plants need. One of the biggest conservatory manufactures used to have a beautifulÂ photo for their advertising campaign of the interior of one of their buildings containing a Persian rug, a cello and a music stand under a parlour palm. Very misleading.
To start with it was difficult. We tried to dispense good and useful advice but we were a bit of a lone voice and probably sounded negative. We could hardly deny such accusations. Slowly, the truth dawned, the demand subsided and now, nearly 30 years later, the subject rarely even gets mentioned. If it does, we'll suggest learning about biological control and using some of the plants we've learned are best adapted to the less than ideal conditions found in the average conservatory. Under 'Plants' on the menu on the home page there are lots of categories - including suggested plants for conservatories.
Trying to grow a plant in a pot is hard enough. Stick it in a hot dry building and it gets worse. By about 2005, heating greenhouses had become officially looney so we immediately dropped some of the more exotic plants we used to do for conservatories (despite their lack of suitability) such as Daturas, Tibouchinas and Bougainvillias. This meant the remaining choice was more frost hardy and one of useful ideas is - try it in the conservatory and it hates it, at least you'll be able to bung it in the garden. Also, just giving a plant a spell outside for the summer could relieve the stress. Plants that would survive with little water (Cacti or Agave) or plants that lived in water (Papyrus) were always the top of the list because they weren't going to suffer from the kind of capricious watering afforded by most human beings.
Also, biological control (essential) and good husbandry were recommended. It was all at variance with what the adverts for conservatories implied.
12.Coppice : Verb. Cut to the ground from time to time - sometimes every winter. The effect is for the plant to produce several new vigorous shoots where there was formerly one. It's used a lot on Eucalyptus as the new shoots produce the silvery juvenile growth loved by flower arrangers. Also on Paulownia as the vigorous new shoots that follow coppicing produce gigantic leaves which people like for exotic gardens. Traditionally, coppicing is usually applied in this country to Hazel (new shoots for stock hurdles and runner beans) and Sweet Chestnut (7 year old growth split and used for post and rail fencing).
13.Creative Maintenance :My original definition of this expression was as follows : Imagine going up to a plant (tree, shrub, bamboo, anything), looking at it and asking the following question : "You're a nice plant but is there anything I can do to you to make you look even nicer?" The answer - in my case - is nearly always a resounding "Yes". It's also defined as the art of subtraction. What you can accomplish by removing stuff. Plants in their natural state have nothing to be gained by 'looking beautiful'. As long as their flowers attract the right insects for pollination, they're happy. The 'looking beautiful' thing is a human construct and is highly subjective. We tend to start by removing everything yellow, brown, dead or broken. Always a good start. Shaping the crown of a tree and cutting away some of the lower branches to reveal a beautiful lattice work of stems beneath. Removing all the bent and battered leaves, old flowers and the brown hairy covering on a palm tree. Clipping a random shrubbery into undulating shapes and twmps (the Japanese call it karikomi) to give them greater definition. Being Architectural Plants where the whole emphasis is on the shape of things rather than the colour of things, there's also - in our case - another definition of Creative Maintenance : gardening. When I first pondered the idea many years ago, the obsession was with the removal of brown bits - particularly on yuccas for some reason. I coined the expression 'Brown Bitting' (Removal of Brown Bits) but allowed it to fall into disuse because of mispronunciation (which indicated misunderstanding) : "Are you Mr White?" "Might be" "Tell me more about this 'Brown Bighting' of which you write" No no no. Wrong wrong wrong. 'Creative Maintenance' has caught on and people seem to understand the endless and enjoyable possibilities. My great ally in this area is Jake Hobson owner of Niwaki - supplier of horticultural stuff from Japan. He wrote a book (that we sell, of course) called Creative Pruning. Same thing. I had dibs on 'Creative Maintenance' so he allowed himself 'Creative Pruning'. It was Jake who introduced me to some chaps in San Francisco - tree surgeons who have taken the art of tree surgery to its logical conclusion. They call themselves Tree Shapers and their splendidly out of date looking website was a revelation. Bursting with ideas beautifully executed with a whole vocabulary to go with it. Even we do 'Vista Pruning' now. Check them out http://www.treeshapers.com
One of the most rewarding experiences is when we're in a customer's garden and we've just turned some boring shapeless old Portuguese Laurel into a sculptural and distinguished piece of topiary in 40 minutes flat. The excitement, the realisation, the enjoyment, the enthusiasm is a wonder to behold. The falling of the scales from their eyes, an epiphany, a Damascene experience. The predatory look in their eye as they look around the garden thinking "Hmmmm... what can we do next?"
14.Crown raised or lifted : An expression used by tree surgeons. It just means cutting off the lower branches on a tree to allow in more light and - often - improve the look of the plant. See Creative Maintenance above.
15.Deciduous : Adjective. This refers to a tree that looses all its leaves in the autumn. Only deciduous trees do Autumn Colour. The time in autumn varies with different trees. Most oaks are evergreen and so it's interesting to note that our deciduous English oaks loose their leaves quite late in the year - presumably because most of their relatives are evergreen. Trees that come from very continental climates (hot summers, cold winters and clearly defined seasons) come into leaf in the spring quite late in Britain - due to their utter confusion created by our climate as to what on earth's going on. Of the plants we grow - Albizia jullibrissin, Ficus carica and Catalpa bungea are good examples. The word is also used in the context of bark. Deciduous bark is one that peels off as the girth of the tree increases. Eucalyptus, London Plane and some of the Maples are examples.
16.Dicot : Noun. A common abbreviation for Dicotyledon. Without wishing to take you back to your botany lessons, the Dicots are the more highly evolved plants that have lots and lots of growing points (e.g. an oak tree) as opposed to the Monocots (short for Monocotyledon) characterised by havingÂ only a single growing point. The reason its worth knowing this is that its probably the most fundamental division in the plant world. The dicots are all the woody trees and shrubs, the monocots are everything else - grasses, palms, yuccas etc.
17.Drought tolerant : When used to describe a plant, this is often misunderstood as meaning that you don't need to water it, even when you first plant it. Drought tolerant just means that the plant has the ability to find water if it's there - not that it will survive without it. When applied to cacti, this might be true but if we describe a plant as drought tolerant, water like mad when first planted. Once established, it won't need watering again - but if you do, it'll probably grow even faster. It's an adaptation to growing in a dry climate. We used to grow a semi hardy palm called Washingtonia filifera the Californian Cotton Palm. They're native to the Californian and Mexican desert and often appear to grow in lines. This is because they'll send their single root from a germinating seed down between vertical sedimentary rock layers. If they find water they survive. If they don't, they don't. When we used to germinate the seed, demonstrating the length of the root and the speed of its growth (3 ft in just a few days) was not just a good party trick - it was a another near miraculous demonstration of the ability of living things to adapt to their surroundings. At that length and at that speed, the plant's chances of survival are pretty high. Even better, the seed won't waste energy by producing its above ground bits (the cotyledon) until water has been found.If you buy a pot grown plant in a nursery, this is not an option open to the plant. It will rely on you to water it until its roots have grown away from the root ball.
18.Dwarf : Noun. xxx
19.Endemic : Adjective. Referring to a plant or an animal as endemic, refers to the fact it exists in a particular place naturally. Much the same as referring to something as native - although sometimes introduced species become endemic.
20.Epicormic growth : The new growth that many (but not all) woody plants (mostly trees) produce from their trunks. We often refer to it in the context of removing it. This is a good way to clean the profile of the base of a tree. Quick, easy, harmless but visually highly effective.
21.Epiphyte / Epiphytic : Noun/Adjective :An epiphytic plant has the ability to grow on another plant - deriving moisture and nourishment from the atmosphere without treating the plant it resides on as a host (that would be a parasite). Most epiphytes grow in areas of high rainfall - bromeliads in tropical America or Common Polypody (a little native fern) on oak branches in south west Cornwall, Pembrokeshire etc. The reason we mention this subject is because there are a few plants we grow ( Fascicularias, Astelias and some ferns) that do - in some parts of the world, grow as epiphytes and we always enjoy encouraging experimentation. Pictures I've seen from south-west of South Island N.Z. of Kauri trees festooned with epiphytic Astelias is a mighty fine site. Could such a thing be accomplished in the British Isles? We do it with Fascicularia bicolor in Sussex. Many more species could be experimented with on the damper Atlantic fringes of the far west.
22.Evergreen : Noun. Refers to a plant that retains its leaves in the winter as opposed to a plant that's 'deciduous' which means it looses its leaves in the winter. Evergreens tend to hail from slightly warmer parts of the world but, as with all rules, this is completely contradicted by most of the coniferous trees that come from some of the coldest parts of the world and are completely evergreen. One common misunderstanding : it's sometimes thought that evergreens don't drop their leaves. All plants drop their leaves but not always in autumn. Many evergreens drop their leaves just before or just as the new leaves arrive in late spring or early summer so we have an expression to emphasise this : 'May is evergreen's autumn'. Some plants you'll hardly notice but ones that do it really conspicuously are Cork Oak (Quercus suber), Holm Oak (Quercus ilex) and Evergreen Magnolia (Magnolia grandiflora). The reason for drawing this to the attention of our customers is so they don't get concerned when they see their evergreens dropping leaves in May. It's meant to happen.
23.Fastigiate : Noun. A word used to describe the tendency of some plants to have steeply ascending branches - giving them either a very narrow or a teardrop sort of shape. One cannot always explain things in evolutionary terms. Is there a point to such an adaptation?
24.Feathered : A term widely used in horticulture. It describes a tree with a single leader but branches from the trunk right from the ground - as opposed to having a clear trunk.
25.Frequently Asked Questions :After nearly 30 years of growing and selling plants, there are definitely questions and statements that come up over and over again. The most frequently heard statement from our customers is : "I'm not a gardener". In fact it's more than frequently heard - it's almost universal. There's something about us that attracts - and always has attracted - people who know what they like, tend to be quite particular but have the confidence to admit they don't know much about gardening. What do we do about it? Almost everything we do and say has a theme threaded through it - a subversive desire to change things; to keep you as particular and discerning and confident as ever but - at the same time - to turn you into a gardener. If we don't do that, we're all going down a dead end street. Treat plants like bits of furniture and flowers like wallpaper and it'll all end in tears.
The information on this here webthing, the care notes provided at the point of sale, the conversations we have with customers, the books and bits of information left lying around and even the rant posters on the subject of plants in pots, how trees grow and what you can do to plants if you're feeling creative. Of all these approaches, what we actually say to our customers reigns supreme. The personal touch - asking about your location, inspecting your garden from 5,000 ft on google maps, being a bit bossy about what you can and can't grow in your garden, discussing husbandry and soil type and even indulging in broad generalities on the subject of design. All of these factors are designed to help - and we really hope they do - but the sinister undercurrent is as follows : we're trying to turn you into a gardener.
Below are some of the questions that come up every day. The questions are followed by a stab at an answer. Not nearly as easy as you might imagine.
a). "How fast does it grow?" A perfectly reasonable question. One could always give a concise but misleading answer like "Six inches a year" or a vague but less misleading answer like "Quite fast". Maybe the most useful is "It should reach about 10ft after 6 years". The problem of course, is that it all depends. It depends on the health of the plant, the type of soil, the nature of its planting, the subsequent maintenance etc etc. The difference between poor plant in poor soil, poorly planted and poorly maintained and quality plant in good soil, properly planted and well maintained is huge. In the case of a Eucalyptus tree, the difference could be 15 fold. Significant. So when people ask this very reasonable question, there's always a temptation to answer : "It depends on how nice you are to it". Describing something as 'slow growing' or 'fast growing' is concise and accurate but the conditions described above can make a nonsense of these statements. Eucalyptus in the right place can grow to 80ft in 25 years or, in the wrong place only 15ft in the same time. The Australian Tree Ferns (Dicksonia antarctica) can form a 4ft trunk in less than 10 years but in a less ideal spot, take 50 years to produce the same growth. Bamboo can reach 30ft with 2" diameter stems in perfect conditions but in imperfect conditions reach 15ft with canes of less than 1" in diameter. And so on.
Back to the question: we do our best to give an indication of rate of growth with the caveat that conditions can make an enormous difference.
b). "How big does it get?" Another perfectly reasonable question and reading the paragraph above will cover most of the answer. An additional factor is that the speed of growth from youth to old age is non linear. It is logarithmic, the inverse of exponential; it grows rapidly in youth, levels off its growth rate in middle age and slows right down to hardly anything in old age. Often we are asked for a small tree that grows to 15ft very quickly. The inference being that it grows rapidly to that height and then stops. Needless to say, no such plant exists. The nearest you could get - we explain - is to have a fast growing tree and buy a tall Japanese pruning ladder and give the tree a haircut at 15ft every year.
Back to the question: we do our best to give an indication of size with the caveat that conditions can make an enormous difference.
c). "How old is it?" Once again, perfectly reasonable but to us, slightly embarrassing. The honest answer is "I don't know" but this answer is usually substituted with an educated guess. It's slightly embarrassing because much of the plants we sell are propagated and grown by us but you'd have to work on the nursery for several years to understand that we have no mechanism to monitor the years of growth as they go by. Apart from working out the relative profitability of a particular plant, there's no reason to do this.
Back to the question: we do our best to give an educated guess. It will be fairly accurate. The question's always asked when it comes to the imported Japanese Niwaki and the big old imported Olive trees. Then it is a guess - not even a particularly educated guess. The Olives have been hacked back so often the trunk could be well over a hundred years old and in the case of the Niwaki, these have often started life on the nursery in Japan as a tree that's been dug up in the wild, been cut down and transplanted to the nursery to be trained as a 'new' plant when the roots may again be well over a hundred years old by the time they get here.
It's interesting writing this down because now I'm beginning to think : "Hang on one cotton pickin' minute, maybe this is exactly what we should be doing..."
d). "Is there anything I can grow on clay?" We're a bit surprised by this one but it comes up over and over again. Mid Sussex is almost all clay and contains many fine gardens and grows the finest oak trees in the land. Clay is full of nourishment and as long as it has plenty of organic content, it grows great plants. Some people have chalky soil, some have sandy soil and both of these are great if you don't like mud but the vast majority of gardens in southern Britain are on some kind of clay.
If you're faced with a new house on the Sussex or Kent Weald you could have a bit of a challenge, it's true. Property developers tend to leave you with a lovely new house and a garden that consists of compacted clay sub-soil covered in 3" of imported topsoil covered in lawn with some not terribly happy birch trees and some equally not very happy 'colourful' shrubs round the edge.
The answer is a war of attrition on your soil. Anything organic - mulch, bark, compost, anything you can get hold of - needs to be dumped on the surface for the bacteria to break down and the worms to assimilate into the soil. Keep doing this and eventually you'll have as lovely a garden as anyone else and it will be on clay. If in these circumstances you feel you're a bit low on worms, get some and introduce them to your new garden. "Get some"? There's even a company called Worms Direct.
Back to the question : Yes, lots.
e). "What if it dies?" It almost certainly won't. Much anxiety surrounds the idea that a plant bought at a nursery might die. Millions of years of evolution and dramatic climatic changes have equipped all living things to survive. Killing things is a major accomplishment - it's difficult. Having said that, it can be done. Buy a plant in a pot and never water it or plant it in the summer and give it insufficient water and it will die. Plant it in waterlogged soil or leave it in a pot with poor drainage and water it mercilessly and it will die. Ignore our traffic light system about frost resistance and leave it out in the cold and it will die.
Environmental symptoms (withering, blackening, poor growth, discoloured leaves, looking bloody awful etc) are a result of what and where the plant is, not disease. Within the first year of planting, disease is incredibly unlikely. It's true that a plant might become infested with an insect pest almost immediately it arrives in its new home but this doesn't threaten its existence and is not a disease. Gardens are full of natural predators that will in time, establish a balance which keeps bugs under control - naturally. Insecticide can be used in a garden but we would very rarely recommend it. Nasty, smelly, dangerous and largely unnecessary stuff. We do have to use it on the nursery but that's intensive horticulture and not comparable with being in a garden. Something that I do if the new growth is covered in black fly is to cut the tips out and destroy the evidence. This way you decimate the bug population and give the natural predators (ladybirds, lacewing etc) a chance to do their job.
Air born fungal diseases are common in our damp climate and also pose a threat to the health (but not the existence) of many plants. In the garden, sections of plant (particularly some conifers and yuccas) get afflicted and it might be worth using a fungicide but more importantly, remove afflicted bits, burn them and use dilute bleach to clean your tools as you go, to stop cross contamination through the tools.
Plant diseases tend to affect older plants and some are incurable but much hysteria surrounds this subject and is blamed on ailing plants when usually, the reason is good old bad husbandry. The two treatments for disease are 1. Surgery (amputation) 2. Medicine (use of various noxious substances). In our experience, surgery is quicker, cleaner, cheaper and more effective. Years ago we discovered that Eriobotrya Japonica (Loquat or Nespilo) when grown from seed was highly susceptible to Apple Scab - a disease usually afflicting appleÂ trees. The plant pathologists had never seen this particular manifestation and amongst much excitement prescribed the standard course of medicine for apple trees - some stuff called Captan, if I remember. Did it work? Sort of but we got bored spraying them all the time and eventually cut the affected plants back really hard (it got in the branches as well as the leaves) and burnt the infected bits. Done. We never saw it again to this day. Having just referred to 'Noxious substances' raises another little problem. Chemical agents that really work are dangerous which is why they work but because they're dangerous, they get banned. Good for the environment, bad for the farmers and the horticulturists but it means that many of the insecticides and fungicides available to the public are fairly ineffective. Another argument in favour of surgery.
Back to the question : Absorb all our good advice, become a gardener and it won't. Very occasionally you might get a plant from an infected batch on the nursery. If they're dying on the nursery, we'll find you another one or give you your money back. That happened once with some ancient grape vine 'trees' we found in Italy. They were horribly diseased when they came in and we ended up burning the whole lot. That was 25 years ago. One learns things.
f). "Why do I kill everything?" You don't, you just think you do. If you're new to gardening, you might fuss over things. "I've paid good money for you so I'm going to be really nice to you and feed you and water you" and kill you. I've done it. Most people have done it. After a while it ceases to be a mystery. It's called 'Killed by Kindness'. Otherwise, read the paragraph above and begin to become a gardener.
g). ''What happens if I remove a dead branch from a piece of topiary?" The concern is that there will be a big hole (there will be) but it will remain a big hole (it won't). 'Nature abhors a vacuum' was first coined by dear old Aristotle and he was right. As true in the garden as in the Infinite Universe. Any gap in a plant and, as long as there's light, new growth will fill it up and surprisingly quickly too. Dead bits often appear in a number of plants used for topiary - Conifers and Box in particular. The fear that "If I cut it out, there'll be a nasty hole" leads to a reluctance to cut it out but if it isn't cut out, there will be no void - no void for nature to abhor and fill. I'm sure Aristotle could have explained it better. Even in Ancient Greek.
26.Frost Pocket : Noun. Cold air is heavier than warm air and runs down hills and - given a chance - collects in pools called 'frost pockets' or 'frost hollows'. You can still find old walled gardens on a slight slope with a large door at the lowest point. Believe it or not, it's there to be left open on frosty nights. I once saw the result of not opening such a door at the walled garden at Borde Hill in West Sussex after an autumn frost. It was like a tide mark - a clearly defined line a few inches thick below which everything was black from the frost and above which, the plants were untouched. If the door had been left open, all the cold air would have flowed out of the door into the woodland beyond. The most brutal manifestation of this phenomena is the katabatic wind. Chilean fiords are famous for them. Cold air from the snow capped peaks will start moving quietly down the slopes but then gathers momentum to the point that these apocalyptic winds will come crashing down to sea level at 70mph. And it's just cold air falling off a mountain as cold air always does.
Almost the first thing we ask our customers is "Where do you live?" One of the many reasons is to establish the topography - are you on a hill (more wind, less frost) or down in a valley (less wind more frost)? It doesn't necessarily have much bearing on what you can and can't grow but it does have a bearing on how some plants will react. Any plant that has the specific name 'Japonica' comes from Japan and will probably start producing new growth as soon as we get one warm day at the beginning of March (it thinks it's spring, we know it isn't). If your garden is a frost pocket, the chances are that the new growth will get frosted, go black and have to start all over again. This isn't a problem although it's sometimes a bit disappointing - it'll just grow again. If you're higher, where the cold air drains away to be replaced by slightly warmer air, the new growth will be unaffected. We'd rather warn a customer that this could happen. Forewarned is forearmed and all that.
Two of the most famous frost pockets in Britain are Rickmansworth in Hertfordshire and Benson in Oxfordshire - the latter often mentioned in weather forecasts as being the "lowest temperature recorded last night". Also, you'll notice that weather forecasts often speculate on the lowest temperatures expected in "sheltered glens"in Scotland. All frost pockets. One of the most obscure studies from the H.M.S.O. (Met. Office) was a study done in the 1950s of a garden in Whyteleafe in Surrey. It seems that its altitude, the fact it was north facing (on the North Downs) and the soil was chalky (well drained soil radiates heat faster than soggy old clay soil and therefore gets colder faster) lead to there being no month of the year that you could guarantee that it was frost free.
The reference to well drained soil above is significant. Another well known frost pocket is Bournemouth Airport. Only four miles from the sea (where you'd expect it to be mild), lying in a bit of a depression (as airports often are) and on very sandy soil. The sandy soil gives up its heat stored during the day very quickly (much quicker than on heavy old clay soil) and the combination of these factors makes this spot on the Dorset coast, so prone to frost that it's often mentioned on weather forecasts as recording the lowest temperature in the south of England on a particular night.
If you've got this far you're a climate enthusiast so here's another good one : one of the rather intense publications I used to get from the Met Office when it was at Bracknell was a record of an infra-red thermal aerial image taken above the intersection of the M23 and the M25 in Surrey on a particularly still and clear night in February. The image suggested that the temperature at the lowest spot on the M25 was -4c. Within about 2 miles at an altitude of 700ft on top of the North Downs, it was estimated that the temperature was +8c. An astonishing difference of 12c.
27.Genus : Noun. This is to do with plant and animal classification. In our case, the way plants are related to one another. See 'Taxonomy' below.
28.Glaucous : Adjective. Botanic-speak for bluey-grey. It's common in the world of plants. Eucalyptus do it a lot and also plants from harsh climates that have evolved a mass of tiny hairs on their leaves to protect the surface of their leaves from the rasping effect of constant wind - especially when it's in conjunction with salt from maritime winds. The mass of tiny hairs often gives the plant a bluey-grey look.
29.Gherkin : Noun. This is a word we use to describe the shape a plant has been clipped to when the clipper has more interest in keeping everything under control than actually bothering to stand back and look at what they're creating. It's true that most plants are much keener on growing up than growing out and therefore the dreaded gherkin is usually the product of merely tidying up what nature has supplied. The trouble is gardening's not really like that and looking at a garden full of gherkins is to most people, deeply unpleasant. This is particularly true if it's a garden full of multicoloured conifers. See blob above.
30.Habit : Noun. This is horti-speak. A word used to describe the way a plant looks - the way the leaves are arranged on the branches, the way the branches are arranged on the trunk, the look that makes that particular plant particular. A useful word. Not my favourite word, but a useful one.
31.Hardy : Noun/Adjective. This is a word used in the gardening world to describe a plant's ability to withstand cold weather. The question of a plant's hardiness must be done in the context of its geographical location. It would be silly to ask if a plant's hardy? Hardy where? The yardstick should be 'would it survive the coldest winter' in a certain place. It can be complicated by soil type, wind exposure and the timing of the cold weather but essentially it's about minimum temperatures. A caveat could be when you have a plant that, in a warmer climate would remain evergreen and healthy but in your own garden might loose all it's leaves and the growing tips might get frost damage but it always survives. I'll let you decide as to whether you'd describe such a plant as 'hardy'. With our professional hats on, we wouldn't.
32.Haircut : Noun. Our own expression (that everyone seems to understand) for clipping a plant. See Karikomi : Noun, below
33.Half Standard : A term used to describe a tree with a 3ft trunk. A Standard (or Full Standard) has a 6ft trunk.
34.Hedge : Noun.Everyone knows what a hedge is. Not wishing to insult anyone's intelligence but there is a question that crops up on the nursery so frequently that I've got to mention it. You can imagine what the question is if I give you the answer : "it grows as tall as you, your step ladder, your head for heights and your hedge trimmer will allow it to grow".
35.Indoor/House Plants : If you're reading this you're human (presumably) and if you're human, you may have a room that you think of as warm, comfortable and light. A plant might disagree with you. It'll probably think your room is dark, dry and not particularly comfortable. Living in a pot in a house is no place for a self respecting plant but fortunately there are a few that don't mind. Some are just incredibly tough (Phoenix canariensis, Agave americana) but most are forest floor plants with large leaves (an adaptation to low light) such as Alocasia, Zantedeschia and Gunnera. Some people are surprised by our suggestions but with skill and space, any plant that's adapted to low light is worth trying as a house plant. Some can get quite big but they either need a large house or office or atrium or they need to get cut back from time to time. Two commonly used 'Indoor/House Plants' are Kentia Palms (Howea forsteriana) and Yucca (Yucca elephantipes). Left to their own devices, Kentias can grow to over 30ft and Yuccas to over 20ft.
Bearing in mind the important understanding that there's no such thing as an Indoor/House Plant (or Conservatory Plant, or Pot Plant or Wall Shrub for that matter), much can be learnt by observing the behaviour of plants indoors. Some might respond to electric lights nearby (the wavelength of light used by plants is little understood), some might enjoy a spell outside from time to time, some will do better by a window, all might get bugs (see Pests and Diseases on this page), all will benefit from having their leaves dustedÂ and all need a saucer to sit in to stop the floor getting wet.
Like most establishments, the House Plant Industry is conservative. Understandably, they stick with what they know but experience has shown us that there are huge numbers of plants worth trying and occasionally one is genuinely surprised at what works and what doesn't. The plants we list in this category have all been tried with conditional (obviously) success. There are more possibilities than Swiss Cheese Plants, Rubber Plants, Ficus benjamina and Poinsettias.
36.Indumentum : Noun. Dusty stuff that exists on the leaves and young shoots of some leaves and comes off in your hand. Why's it there? No idea - but probably protective in some way. Of all the plants we grow there are only two worth mentioning as the indumentum can be slightly irritating to the skin so it's worth rolling your sleeves down and keeping your mouth shut when you're working on either Fremontodendron californicum (Flannel Bush) or Tetrapanax papyrifera (Rice Paper Plant).
37.Karikomi : Noun. This is the word Japanese gardeners use for what we'd call lumps and bumps - clipped mounds. One throws it into horticultural conversations from time to time in the vain hope that as a result one might be taken seriously. The translation? 1. Prune 2. Haircut. Interesting - see Haircut : Noun, above.
38.Microclimate : xxxxxx
39.Micropropagation : Noun. 'Cuttings' are bits of plant stuck in some compost under conditions of controlled heat and humidity and left there until they produce roots and become a new plant. Some plants can only be propagated similarly but using the actual growing tip - known as the meristem. If you were to try this in a conventional propagation house, unfortunately the little bit of plant material would rot away long before it had a chance to grow. So, someone had the bright idea of doing it in clinically clean laboratory conditions. The meristem (bit of growing point, usually a bud) might only be a few millimetres across. It's cleaned in the lab (always tricky as the cleaning process can sometimes kill the bud as well as its contaminates), it's then put in a petri dish (or, more often, a recycled margarine tub) on a complex nutrient solution that looks like agar-agar jelly, covered securely and put in the growing room. This is kept at a constant temperature under strictly controlled lighting. If the bud was contaminated, it will turn black. If not, with luck, it will grow on the solution and once big enough, it will be divided up in a special flow cabinet (clinically clean conditions) and the bits put back on the nutrient solution. You keep dividing and dividing and when you've got enough bits, you leave them and, again, with luck, they produce roots and leaves and you have a tiny little plant called a micropropagule. This has to be weaned in a conventional prop house - toughened up and made to stand on it's own two feet. That was quite a simplified account. You sometimes hear the nutrient solution referred to as M & S. This stands for Messrs Murashige and Scooge - the two Californian scientists who pioneered the process in the early 1960s.
40.Monocot : xxxxxx
41.Mound : Noun. xxxxx
42.Multi stemmed : xxxxxx
43.Niwaki : xxxxxx
44.Pathogen : xxxxxx
45.Pests and Diseases : xxx
46.Posh : Noun/Adjective.Whether we like it or not, there are social stratifications of plants as there are with society. As you well know, we are a company with impeccable credentials when it comes to political correctness and so when we use the expression 'posh' or even 'dead posh' it is merely an observation, not a value judgement. It refers to the fact that a plant is considered acceptable (posh) or even highly acceptable (dead posh) by our social betters. But why? I pondered about this for many years and the explanation is simple; it's nothing to do with the innate good taste of the privileged few - it's just a function of how long a plant has been in cultivation. The longer it's been around, the more acceptable it is and thus, how posh it is... This necessarily means that the 'posh' plants all come from Europe. If they've been in cultivation in Britain for 500 years, they're not going to come from China, Australia, or South America. Five hundred years ago, most people thought you'd fall off the edge of the world if you tried to go that far. They will be native trees or European natives ; Holm Oak, Phillyrea, Portuguese Laurel, Holly, Bay, Beech, Hornbeam etc etc. As simple as that. One of the few exceptions could be Magnolia grandiflora from America. This was first introduced to Britain in the early 18th century - very very much earlier than most of our familiar garden plants. Is it posh? Just about. If you think the social stratification of plants in Britain is extreme - try Italy. I met a very grand Italian lady who'd committed the appalling faux pasÂ of ordering a mass of Cherry Laurel (Prunus laurocerasus) for some hedging for her Tuscan villa garden. Her head gardener, accompanied by his entire staff arrived at the house and explained that either they (the Cherry Laurels) went or they (the entire gardening staff) went. The Cherry Laurels were immediately replaced by highly acceptable Portuguese Laurel (Prunus lusitanica). Phew.
47.Pot Plants : xxx
48.Prostrate : xxxxxx
49.Provenance : Sometimes used for antique furniture, sometimes used for plants. It refers to where something comes from. The context should explain whether the reference to provenance comes from where the material came from (seed or cuttings, perhaps in London) or where the plant is indigenous to - maybe Patagonia or New Zealand. Both could be a plant's provenance.
50.Relic : Noun.This is interesting. For many years I was baffled by the fact that there were plants from frost free areas of the world that could survive temperatures as low as -15 degrees centigrade in Britain. One thing I had noticed however is that they all came from islands. Madeira, Canaries, and Southern Californian Islands, in particular. It's often a chance remark that casts light on a mystery. My hero was a quiet nurseryman from Devon. We were walking round the nursery one day and I was expressing surprise at the ability of Euphorbia mellifera to survive in Britain considering it was native to virtually frost free Madeira and yet other plants native to Madeira couldn't withstand any frost at all. "Relic" he said, ever so quietly. "Eh?" I replied. Admittedly, getting the full story out of him was like extracting teeth but eventually the penny dropped: it's all about successive ice ages. Imagine a huge geographical distribution of Euphorbia mellifera before the last ice age (or maybe even the ice age before last) - throughout most of Europe and North Africa and this would include the island of Madeira. The polar ice cap expands, killing millions of plant species it its wake and guess where the only place that's warm enough for Euphorbia mellifera to survive? Because it's an island, even in the ice age, it would have been relatively warm. And the plants we think of as native to Madeira that will tolerate virtually no frost? These would have been introductions (probably by birds) since the ice age.
There's a nice little phenomenon that's associated with the effect on plant populations of expanding ice caps : the orientation of obstructions to plant migration. Consider the Alps and Pyrenees. Both mountain ranges lie east to west and would have been a huge impediment to the southerly migration of plants which would have caused many to be wiped out. Now consider the orientation of the Andes and the Rockies - north south. Particularly in Chile and Argentina, there are many plants that - as a result of their unimpeded migration both up and down the Andean valleys - now have a geographical distribution thousands of miles of latitude. This means you can get the same plant as far north as Southern Peru and as far south as Southern Patagonia - an extraordinary 2500 miles. In our experience though, this can effect the hardiness of a single species according to their provenance; an example of the tree Maytenus boaria from Southern Patagonia could be very much more resistant to frost than one from Southern Peru. You can therefore understand that when we're searching for material for propagation of plants to be grown in Britain, we're always looking for plants from the coldest places - from the highest altitude and / or from the furthest north in the Northern Hemisphere and the furthest south in the Southern Hemisphere. And so it goes on...
51.Shrub : Noun.An unfortunate word not helped by the Knights Who Say Ni and the fact that possibly the dullest sounding phrase in the English language is 'Medium Sized Shrub'. However, there's nothing wrong with the thing itself: a woody plant, evergreen or deciduous, that never gets taller than... 10ft? The great thing about shrubs is their potential for Creative Maintenance. We fiddle with everything and the very last thing you want to do with a shrub is to leave it to its own devices. Clip it into a blob, plant it with some of the same and let them undulate or - best of all - train it into a shapely little tree. Raise the crown (cut off the lower branches) to expose the network of branches beneath and round the top into a pleasing dome. All good fun.
52.Species : Noun. xxxxxx
53.Standard : Noun. A term used to describe a tree with a 6ft trunk. A Half Standard has a 3ft trunk.
54.Stool : Verb. xxxxxx
55.Suckers : Noun. xxxxxx
56.Taxonomy : Noun. The science of classifying plants - how they are related to each other. Even for the most unambitious gardener, having a sketchy idea of the meaning of 'Family', 'Genus' and 'Species' is really helpful. Here's a tiny little lesson : Ceanothus arboreus & Ceanothus azureus. Same 'Genus' (Ceanothus), different 'Species' (arboreus & azureus). Eriobotrya japonica & Lyonothamnus floribundus. Different 'Genus' but same family (the Rose family - Rosaceae) and you'd never know that, would you? You have to learn what plant's in what family and when you do it's helpful and interesting because you suddenly discover family traits and understand why some plants look completely different but you might notice how their flowers are remarkably similar and it all makes wonderful sense. You suddenly understand why English Ivy (Hedera helix) and New Zealand Lancewood (Pseudopanax crassifolia) have the same flowers - because although they grow 12,000 miles apart, they're quite closely related and are both members of the Aralia family. Taxonomy is carried out by Taxonomists and their work used to be based on the structure of flowers but is now done by DNA profiling. Exactly how this is done, I have no idea but it has meant we're on shifting sand - plants that have always been thought to be related are - according to the new order - not. Sometimes the names change which takes some getting used to. The taxonomists are also the people responsible for naming the plants. It's a big subject...
57.Tender : Adjective. A particularly horticultural word for describing a plant as not being entirely (or at all) frost hardy.
58.Topiary : Noun.The art of fashioning plants into shapes using shears, clippers etc. The overwhelming element in this practise is a rounded, dome-like shape - almost undoubtedly because of most people's preference for this shape. We have always sold clipped Box plants in the shape of balls and cones and could never ignore the fact that we would, on average, year in and year out, sell about 40 times more balls than cones. This is significant but unsurprising. The rounded dome shape is the one associated with mature and beautiful trees, of gentle hills and a quiet, restful and tranquil landscape. Surely these are elements that many gardeners are looking for in their own garden.
59.Tree : Noun. xxxxxx
60.Tropism : All who studied botany at school will remember this. It's a word to describe the tendency of a plant's parts (above or below the ground) to grow in a particular direction : Towards light (Positive Photo-Tropism), Away from light (Negative Photo-Tropism), Down, towards gravity (Positive Geo-Tropism) and Up, away from gravity (Negative Geo-Tropism). One hopes the names are self explanatory.
Not surprisingly, most plant roots are positively phototropic and most plant branches are positively phototropic. Some plants are more positively phototropic than others which has a bearing on how you position them. Plant a Pine, a Maiten or a Eucalyptus next to a wood and they will grow towards the light so enthusiastically that they'll bisect the angle between the wood and the ground - growing at 45 degrees.
61.Twmp : Noun. Welsh for mound. Powis Castle near Welshpool in east Wales is famous for its clipped yews in giant blob form. They are often referred to as twmps. Much of the artist David Nash's work is influenced by these and he produced a little book with drawings - called Twmps. One of the highest mountains in the Black Mountains on the Hereford border is (In Welsh) known as Twmpa. The fact that in English it's called Lord Hereford's Knob is irrelevant. It's not a translation from the Welsh and it certainly isn't funny.
62.Undulation : Noun. xxxxxx
63.Urban Heat Island : The centre of a town or city is always warmer than the surrounding countryside and the meteorologists' term for this phenomenon is the Urban Heat Island. It's true of even small towns but the bigger the built-up area, the more dramatic the effect. People often notice how spring comes earlier in London and sometimes refer to it being 'a couple of degrees warmer'. It can be much more than a couple of degrees but the difference is at its most dramatic when it comes to minimum winter temperatures and this - as gardeners - makes a huge difference to what can be grown in a heavily built up area, as opposed to cold rural areas. What will survive and what will die.
Cold nights in winter come when the sky is clear and there's no wind. If you're in London on a night like that, you can feel the temperature dropping and then - nearly always just above freezing - the temperature stops dropping. The effect of stored heat in millions of cubic metres of brick, stone, concrete and tarmac, aided by thousands of boilers and millions of human beings. Out in the country, at the same time, the temperature just keeps falling and falling. The coldest temperature recorded in Sussex over the last 25 years was in February 1991. We recorded at the old nursery in Nuthurst -17c. The same night in the tiny back garden of a friend's house in Notting Hill Gate, we recorded -4c. These are not proper screen temperatures that would be recognised by the Met Office but they were still correct and our interest is in relation to plants and where they will thrive and survive and where they will not. A temperature difference like that immediately explains the existence of those huge Canary Island Date Palm (Phoenix canariensis) on Kensington High Street, Orange Trees in roof gardens down the Goldhawk Road and various discarded sub-tropical house plants that have survived quite happily outside in SW1. Avacados, Yuccas from Guatemala, Kentia Palms and Ficus benjamina. We always say to our customers that you can grow almost anything if your phone number begins with 0207. We call it 0207 Land.
When I started the nursery - hungry for information - I got in touch with the Met Office at their old HQ in Bracknell. They were wonderfully helpful and kept bombarding me with HMSO official leaflets and studies on climate and microclimate during the 20th century. One was a study done in 1953 where a Landrover equipped with highly sophisticated temperature measuring equipment, drove on a clear, cloudless, still winter's night from Epping in Essex to Weybridge in Surrey in a straight line through the City of London to measure the temperature gradient. It confirmed what everyone knew already - the nearer the centre of London (and any other built up area) you get, the warmer it gets.
One of the few times I was excited about getting a new car was when I bought one with a temperature gauge. They all have them now but in the 1980s, this was very unusual. Recently I bought a car with Sat Nav.I don't have the faintest idea how to use it but I put it on sometimes because - miraculously - it gives you your altitude. The combination of knowing the temperature outside, and your altitude and observing the effect on temperature of altitude and the amount of buildings around you, turns your car into less of a means of transport and more of a mobile meteorological station. Heaven!
64.Wrapping for Winter :A subject about which I have to admit to some agnosticism. Do I really want to look at a straw stack or a cylinder of chicken wire filled with dead bracken in the middle of my garden for the entire winter? Or even worse, my beloved exotics wrapped up in bubbly plastic and brown sellotape.
In Japan they have a tradition of wrapping some tree trunks and Cycads for the winter using rice straw in some of the colder parts of the country. It's often a work of art that will have taken several people several days but it works and it looks beautiful.
In this country there are similar traditions but they tend to surround edibles rather than exotics e.g. figs had bracken tucked round them and pineapples were grown in heated glass frames.
The art of wrapping exotics to get them through winters that they were never designed to get through is in its infancy. We're often asked how to wrap plants for the winter as if there are established rules surrounding the subject. Sadly, there aren't. It's mostly down to your own ingenuity, your desire to do it and a knowledge of the plant
Having said that, here are some ideas and observations from our own experience :
First :wrap according to the weather forecast and not the calendar. Some winters are so mild, wrapping is not necessary. If the forecast is for very cold weather, get out there and start wrapping. You've got to be a bit of a meteorologist to do this but that's all part of the fun of becoming a gardener.
Second : don't leave plants wrapped upfor too long - it'll do more harm than good. Wrap up a Cordyline in October and unwrap it in April and it will be a dead and smelly mess. Just do it when it's about to get cold and unwrap it as soon as the cold is over.
Third : use natural materials where possible - they allow some ventilation. Straw and hessian sheets are best and horticultural fleece is good but avoid plastic as it will just cause the poor thing to rot due to lack of ventillation.
Dicksonia antarctica : There's no point tying up the fronds as they always look so tatty when you unwrap them so cut the fronds off and wrap the trunk in layers and layers of hessian or fleece. Some people say they'll benefit from having straw in their crown. I find it all very inconclusive because it's clear that the frost hardiness of this plant varies enormously. One thing that does work is to build a stack of straw bales round each plant. We actually used to do that at the old nursery but that part of the garden ended up looking like a farm yard for three months every year and can you still get small straw bales anyway?
Musa basjoo : this is worth doing just to preserve the trunk and using the straw bales undoubtedly works. Cut the leaves off once the frost has got them and protect the trunk by whatever means you have at your disposal. A very cold winter will cause the trunk to collapse so protecting the trunk is worthwhile.
Cordyline : tie the leaves up if you can reach them. The old leaves will go some way to protect the tender growing points. Sticky tape works well
Phoenix canariensis : gaffer tape's the only thing strong enough to hold it all together. Once it's in a column of leaves, try wrapping in layers of fleece and more gaffer tape. An ugly white column. You can buy rush matting quite cheaply. Applying this round the fleece provides an aesthetic advantage.
Smaller herbaceous tender exotics in cold gardens : Echiums, Geranium madarense, Melianthus etc. : You can construct a little tent over them using sticks and fleece but it will only give minimal protection unless you introduce a heat source like an old light bulb (new light bulbs are so darned efficient they hardly give out any heat. What is the world coming to?). Alternatively, keep them in big pots, drag under cover in winter, or move to Penzance, Paddington or Puerto Rico.