1.How to Plant...2.How to Stake & Guy...3.How to Clip...4.How to Water...5.How to Grow Indoor Plants...6.
How to Grow Conservatory Plant...7.How to Grow Plants in Pots...8. How to understand how Plants Grow...9.How to Control Pests & Diseases...10. How to understand Creative Maintenance...11.How to stop worrying about Roots & Foundations...12.How to stop worrying it's going to die
1.How to Plant : This paragraph is cut, pasted and edited from :THE GOLDEN RULES OF PLANTING ( No.5 of The Rants found under 'Plants')
So much confusion. Ask ten different people and you'll be told ten different things. We do sympathise but here's a summary of what, over many years of planting we've learned are :
1. VITAL 2. OKAY 3. MAD
Plant High : Most people have clay soil that can lay wet all winter and rot roots. Plant high, mounding the soil up round the root ball and the plant has a much greater chance of success - it's got something light and well drained to root in to. If you have beautifully well drained soil this may not be necessary - but it usually is. Surround with a large area, clear of grass or weeds.
Use mulch : This is mulch from a mulching machine - not spent mushroom compost or green waste from the local tip. Buy in bulk (not bags, too expensive) and be generous. Bacteria break it down, the worms assimilate it into the soil. The maximum effect for the minimum work and the plants love it. If you use extra compost, don't put any under the root ball. This can cause the rootball to sink which is the equivalent of planting low. If soil is too deep round the base of a woody plant, the bark will rot. This is the same as a rabbit ring-barking it. It will die.
Stake or guy really, really well : This is the thing people have the greatest trouble with. Not unsurprisingly, we have a lot to say on the subject. Whether to guy or to stake? How many stakes? How to stake? This needs a discussion with us - please ask.
Protect from rabbits, deer and anything else that attacks plants : Easier than the staking but just as important. Ask for advice.
Don't over water : People always worry about how much to water but it's not as hard as people think. In our experience more plants are killed by over watering than under watering. If they have too little water, they can drop their leaves and wait. If they're sitting in a bog, all they can do is have their roots rotted and die. Bamboos and some herbaceous plants often benefit from plenty of water but most of our plants come from parts of the world with long dry summers and once established they never need watering. There's a common expression in horticulture -Killed by kindness.Some fast growing plants do need lots of water to get established - Acacia and Eucalyptus come to mind
Planting with extra peat or compost : Why? What's the point? We do this very rarely - usually only when specifically asked to. Plants have got to make a go in whatever soil they're in. A bag of peat isn't going to make much difference. However, we DO use masses of mulch and let the bacteria and the worms do their work.
Using those watering tubesÂ : Some people are very keen on these tubes that you pour water down to get to the roots. They're probably marvellous but we never use them and feel the way we do it is perfectly adequate.
Feeding : When customers ask -Shall I feed it? We usually say 'No'. It's sometimes another case of 'Killed by kindness'. We've all done it. "I paid a lot of money for you so I'm going to be terribly nice to you and give you lots of water and lots of food. And kill you".Unless you're on very poor sandy or chalky soil, just obey our other rules, don't feed, and you'll begin to realise that, with a bit of common sense, killing plants isn't easy, it's extremely difficult.
Using that plastic woven membrane stuff to suppress weeds : A layer of plastic over your soil means you can never improve the soil with organic mulch and you can never see what your soil's like. It look hideous (it's often covered in bark chips which blow around exposing areas of tatty looking plastic), it doesn't let all the rain through so it either directs too much water into or away from a rootball (depending on whether the plant is planted high or low) and it certainly doesn't suppress weeds as they can root through the membrane given a chance. If you want to control weeds, use a good old fashioned hoe.
Torturing your plants in pots : See Rant No:4 for more on this thorny subject.
2.How to Stake & Guy: So much confusion on the subject of staking, guying and planting. Ask 10 different people and you'll get 10 different answers. I'm going to restrict myself to explaining how we do it and have been doing it for 30 years but before that, it's worth reminding the reader that the reason there seems so little consensus on the subject is because - like so much gardening - it's an entirely man made construct. In real life, a seed will land on the ground (how it got there is a whole other subject and not for now) but if it's ripe and the conditions are right, it germinates and becomes a tiny seedling and if it's very very lucky, it will one day turn into a mature plant and pass its progeny on to ensure the continuation of its species. It will grow slowly, reaching for the light, competing for food and water with other plants and it won't need staking.The idea of growing plants in plastic pots and then putting them in the ground will certainly increase the chances of success by a huge order of magnitude but it's still a subject that requires some consideration. In a nursery, plants won't struggle for food and water (at least they jolly well shouldn't) so they'll grow faster than in the wild and will probably need some support when young. How do you know whether or not to stake? It's usually obvious. If it stands up on its own and the root ball is big enough and it's not in a windy spot, it should be fine.
If you buy stakes and tree ties from us, you'll get a piece of paper with useful drawings and diagrams. I will endeavour to figure out how to link those drawings to the webthing and I'm assured that we will produce an instructive video on the subject. One day. When we have time. In the meantime : the idea is to use (preferably) two stakes driven into the ground opposite each other between the existing rootball and the side of the hole you dug. Drive them in with a large sledge hammer (or get hold of a post rammer if you have lots to do) and get them in as perpendicular as possible. The perpendicularity will have no bearing on the success of the tree's establishment but will look so much better than a wonky one. The ties we provide consist of a plastic tube, a long strap and two large headed nails. Pass the strap round the tree trunk and put the two ends through the tube which should be cut to length (from the stake to the tree). Then pass the two ends that have emerged from the other end round the stake, overlap them, get them nice and snug and whack the nails through the overlapping straps into the stake. Not into the tree please. Then do the same just above or below the other one - pulling in the opposite direction. When done, if necessary, cut the stakes off so they're the same height. Clear as mud? Alternatively, ignore all these words and just use your common sense.
Guying a tree is used when it's such a big tree in such a windy place that stakes will be insufficient. Of all the trees we grow, Pinus pinea (The Mediterranean Umbrella Pine) is the only one we guy regularly. The reason is partly because they're good in very exposed sites but they're also remarkable top heavy. It's all that resin. We sell guying kits with instructions but here's the essence : three stranded (easier to use than a single wire line) galvanised cables are passed though some black rubber tube that protects the lowest branches on the tree. The cable emerges from the tube to be clamped onto itself using little U bolts. These ties will be arranged in a Y shape (120 degrees between each other)to give maximum stability and attached to stakes driven into the ground with wire tensioners attached to play around with the tension and the perpendicularity of the tree once planted. Try to keep these stakes within the bed you create for the tree. It makes mowing easier and less likely for someone to go flying when they trip over the stakes sticking out of the ground. Obviously, the stakes would be cut off just above ground level. All of this stuff can either be bought from us or a fencing supplier. If you're concerned that the guys will become two tight as the tree grows and the branches used to attach the ties, rise up, then your understanding of how plants grow is severely deficient and you must read Rant No : 2 - Tree Trunks aren't like Toothpaste.
3.How to Clip : If it's really big, we might occasionally use a petrol driven or electric hedge trimmer but nearly always we use our Japanese Okatsune shears - for everything - no matter how big or how small.
In order to avoid cross contamination of any fungal disease that might be present, we always have a bucket of 5% bleach solution (household bleach or Milford Solution) by our side. Stick the tool in the bucket (even an electric hedge trimmer if you can manage)Â ever few minutes or between individual plants, count to five and carry on. The bleach will kill any fungal spores on the tool and stop further infection. We started doing this on the nursery many years ago when we discovered that some Ligustrum delavayi (small leafed topiary lollipops) from Italy with strip canker (a horizontal scar all the way down the trunk) had spread to our home grown Ligustrum lucidum (closely related evergreen trees). We introduced the use of dilute bleach and it was so successful that subsequently, it became a bit of a religion and something that now everyone accepts. A bit of a fag but well worth the trouble. One can liken this process to the dramatic decline in the frequency of septicaemia in Glasgow Royal Infirmary after Joseph Lister introduced the use of carbolic acid as an antiseptic in the 1870s. Lister's method was life saving and life changing. Our method is a good way to save yourself a bit of hassle in the garden from time to time. Same idea though.
Not unreasonably, we're often asked when's a good time to clip. Avoid the autumn as cutting a plant back encourages the sap to rise and encourages new growth. Clip in October and a severe frost in November could damage the plant. This doesn't apply in central London and mild coastal areas but is still a good general rule. If a plant is particularly slow growing, clip it in March before the new growth appears but mostly, clipping is done during the summer, while the plant is growing. The frequency is entirely proportionate to your desire for a crisp, well tailored look or a more informal look. On the nursery, we know that well clipped topiary sells better than informal topiary so Box plants are clipped 6 or 7 times during the summer but if you were to do your clipping once a year and you're happy with the effect, that's fine.
Here's an important thing : Things that are obvious are really nothing of the sort. They're just obvious, after you've realised them. Then, they're obvious. Here goes : If you're creating topiary, you presumably want the plant to become dense and thick and well defined. The basis of topiary is the fact that when a woody stem is clipped it bifurcates (divides into two) and successive cutting will therefore allow the plant to become dense with stems. If you leave a stem so it's 6" long and then cut it back to where you want it to be, it will bifurcate once. If, during the time it took to grow to 6", you were to cut it back 6 times (every time it grows 1"), think how much more bifurcation there will have been! So, if you want your topiary to be crisp and thick as soon as possible, clip it as often as you can and you'll be amazed how quickly the process is accomplished. Cut it once a year and you'll be amazed at slow the process is. Make sense?
What can one say about shape of topiary? There's a popular belief in lollipops. A ball on a stick. The trouble is that plants grow up, not down and therefore balls always look thin at the bottom and there's a touching belief that one day it will be nice and dense at the base just as it is at the top. It won't. It'll always be thin at the bottom. We have a simple solution. Make it flat across the bottom like a mushroom. Because we like to show off our incredible grasp of foreign languages, we call them Funghi. Not only does it work brilliantly but the shape (we and most people think) is more pleasing. Just remember when clipping - the the line across the bottom is just as important as the curve over the top. I could witter on about various shapes (which I will in a minute) but attending one of our courses on Creative Maintenance would be instructive.
More on shapes : most plants grow up, up, up. Some people's idea therefore, is to clip plants tall and narrow but neat. We call these gherkins and they're usually pretty unpleasant to behold and seem to have more to do with taking control of the garden than creating a beautiful garden. Believe it or not, most creative ideas in the garden are borrowed from the nature. Scan the horizon where the landscape is dominated by mature old trees. Their majestic heads are domed and wide and the trees look almost squat. The Japanese are nuts about clipping stuff and they get this 'almost squat' thing. Donuts - flat topped balls, sometimes referred to as pillows and other things -the vocabulary goes on and on but we definitely have a weakness for donuts and an antipathy towards gherkins.The shapes, that is.The traditional market for clipped Box is dived between Cones and Balls. Historically, we sell 50 Box Balls to every 1 Cone. Cones occasionallyÂ have their place but it's quite clear that people prefer the shape of Balls to Cones. To us, it's a more pleasing shape and it's a more natural shape. Maybe if you lived in Siberia where the conifers are all conical, your perception might be different. Who knows.
Still on the subject of shapes and geometry : Cones and Pyramids are different but they seem to get confused. Cones are circular in cross section (think of ice cream cones upside down) and pyramids are square in cross section (think of Egyptian pyramids). Cones are much more common in the horticultural industry because they look a bit like pyramids but are much quicker to produce. Pyramids are very posh and beautiful but take forever to produce those nice crisp arrises down their corners. The two terms are different but pyramid is often used when cone is meant. If you use a powered hedge trimmer, once you've built your pyramid, it's actually much quicker and easier to clip. Bosh, bosh, bosh, bosh, done.
4.How to Water: How much water should I give it? Another reasonable but fairly un-answerable question. You've got to get in its little head or whatever its planty equivalent is. You've got to understand what it does, what it's doing, what it needs and you've got to know a bit about the plant - and that's where we can help.
As a general rule, if the weather's warm and the plant's growing vigorously, you'll be hard pushed to over-water. If the weather's cold and the plant isn't growing, it will need little water. If it's windy, the moving air increases the rate of transpiration (loss of water from the leaves) and more water will be required - whatever the season. If it's deciduous and it's winter, it will have very little use for water. If it's herbaceous and dies down in the winter it will need water in the spring when the metabolism of the plant goes from 0 to 60 in just a few weeks. If it's famous for growing fast and getting big quickly (e.g.Eucalyptus,Gunnera,Canna,Cynara, Bamboo), it can only do its thing with masses of water. If it's famous for growing slowly (e.g. Dwarf Pines,Cycas), give it more water than it has use for, the soil will become a bog, the roots will rot and the plant will die.
Remember that a plant that's just been removed from its pot and put in the ground, might as well still be in its pot as far as watering goes. Even if the ground's wet, the roots on the side of the rootball will not be able to take up sufficient water. For the first few weeks after planting, water the rootball as if its still in a pot. Once the roots have grown out of the rootball and into the soil, it's on its own. Rarely more than a few weeks in spring and summer. Longer in winter but then in the winter it won't be growing so will have less need for water.
One thought to hang on to : it's clear that more plants are killed by over-watering than by under-watering. Over watering rots the roots and the whole plant will collapse quickly. It's called Killed with Kindness. "I've paid good money for you so I'm going to be really nice to you and water you and feed you constantly. And kill you". We've all done it when we started gardening but we all learned not to. Or gave up gardening. One of the two. Unfortunately, the early symptoms of both drought and drowning are similar. The reason's the same (water is not reaching the extremities of the plant and the tips are dying) but the causes are very different. In drought there's no water reaching the tips because there's no water but in drowning there's no water reaching the tips because it's so wet the roots have rotted.
A word on Drought Tolerant plants : Much misunderstanding. Except in the case of a few peculiarities (e.g. Cacti), being drought tolerant merely means the plant's good at finding water - not that it can tolerate an absence of the stuff. This means that plants famous for being drought tolerant (e.g. Cupressus sempervirens, Cistus and Rosemary) need lots of water when first planted. Once they've sent their roots down and found water, they'll probably manage without ever being watered by humans. Unless they're in a pot, of course...
...plants in pots :A few like it wet (e.g.CyperusorGunnera) so if the pot's in a tray, just make sure there's always water in the tray. As long as you know (or strongly suspect) that the roots have reached the bottom of the pot. Some plants are what we call Good Wilters. A Good Wilter (e.g.Eriobotrya) is one that droops its leaves when its dry, you give it a drink and half an hour later its all perky again. Very convenient. The drooping business is its way of dealing with drought. It closes down and flops in order not to loose any more water until some more appears. Then you get the ones that will just stop growing but look okay in drought conditions (e.g. Bananas). The huge Banana-like plant known in Ethiopia as Ensete (Ensete ventricosum) can survive quite happily for two years without rain. It just stops growing. Then you get the Bad Wilters (e.g Bamboos). These start drooping when too dry but the process is irreversible. Once they've started a wilt you can water them as much as you like but it's too late! They'll regenerate from the roots but they won't look nice again for a year or two. These are the ones we warn people about when the occasion arises. Bamboos in pots in a roof garden really must have an irrigation system or a pretty religious approach to hand watering.
The Parable of the Two Bananas. When I started the nursery, I had to learn quickly how to advise my customers on how to grow our plants. Certain questions and comments by customers stand out in my memory. Here's a good one : "I don't understand it. I've got two bananas in separate pots and I give them the same amount of water and one's doing really well and the other appears to be dying and they're right next to each other". The answer? You're giving exactly the right amount of water to the happy one and that's why it's happy. You're giving too much to the unhappy one and it's roots are rotting and it's growth rate is probably going backwards and you continue to water it so you are compounding the problem and if you continue, the plant will give up and die. So how did this come about? At some crucial point (probably over the course of a day or two) the balance tipped for the poorly one. Suddenly, it couldn't use the amount of water being provided and because the customer carried on, the problem became worse and worse. All they had to do was to notice that one wasn't doing as well as the other and stop watering the one that wasn't doing so well and let it catch up. Think about it. Get the Parable of the Two Bananas and you've learned a lot about watering plants.
Irrigation systems : We swear by them. We instal an irrigation system in almost every garden we build. We use a tiered system so the plants that need lots of water are at the end nearest the tap (usually Bamboos) and then there's a small tap on the irrigation pipe so that other plants can be isolated from the system if it's a wet summer and they don't need the water and then, sometimes, another isolating tap for ferns and small slower growing plants. An irrigation system is not a sinecure. It needs an intelligent human behind it to manage it but it's a fantastic way to get new plants established. The systems are plastic and relatively inexpensive and after five years might be so dilapidated that they can be abandoned but their job is done. On a roof garden, it'll have to be perpetual but as one doesn't usually have dogs, rabbits, deer and foxes (destroyers of irrigation systems) on a roof garden, this is easier to accomplish.
One can hardly blame customers for asking that frequently heard question : "How much should I water it?" but after reading the above you might understand why there's no simple answer. The simple answer is "Not much" which doesn't really help at all. Now we can say : "Read the bit on the website called How to Water"
5.How to Grow Indoor Plants : The following paragraph is some helpful hints on indoor plant husbandry followed by the cut and pasted bit from the glossary of terms on indoor plants:
Selecting the right plant is important. This depends on your likes and dislikes and the plant's likes and dislikes. Do you like it? Does it like it where you've put it? You'll soon find out. To find the list of plants that we grow that might be suitable candidates see under House Plants/Indoor Plants. Also watering, feeding, pest control, repotting, shaping and tidying.
Watering is covered in How to Water on this page.
Feeding can be done with a few drops of Baby Bio (sea weed extract) in the watering can every time you water it.
Pest Control is under Pests and Diseases in the glossary.
Repotting : Try to use tapered pots. You can remove a plant from a tapered pot but not if it's tub shaped or urn shaped or any shape other than tapered. If you don't want to put the plant in a bigger pot (always a sensible solution for an unhappy plant), take the de-potted plant outside, saw or cut (old saw or carving knife) a slice or two of compost (plus root) off (like the end of a loaf), replace in same pot and fill void with nice new compost. Try to pot on or root prune before it looks half dead rather than after it looks half dead.
Remove yellow, brown and dead bits. Some indoor plants can be cut back if the thing's too big or you want to make a plant happier in its pot by reducing the size. Removal of bits (leaves or branches) will always add to the happiness of a potted plant. Less leaves means less strain on the roots which can't expand (as they would in the ground) because they're in a pot.
Below is the general rant cut and pasted from the glossary of terms. It's designed to manage your expectations!
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 asAlocasia, ZantedeschiaandGunnera. 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 in the glossary), all will benefit from having their leaves dusted 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.
6.How to Grow Conservatory Plants : xxxxxx
7.How to Grow Plants in Pots: As we relentlessly point out - plants don't grow in pots, they grow in the ground. However, on this occasion, let's put a more positive slant on the subject. Tapered pots are a tremendously good idea (like traditional flower pots) for the simple reason that you can easily remove the plant from the pot to either put it in the ground, put it in a bigger pot or to root prune it. Root prune? Cutting a great slice of root off the exposed root ball like the end of a loaf of bread, sticking it back in the SAME pot and filling the void created with some nice fresh compost and some good food. This can rejuvenate an unhappy plant to an extraordinary extent. Do it with a bread knife, an old saw, a hatchet - whatever cutting or sawing implement you have to hand. Pots that are either parallel sided or come in at the top may be a great idea from an aesthetic point of view but from a purely horticultural point of view, they're crap. Good husbandry can then only be done with the aid of a sledge hammer or an angle grinder -Â to destroy the pot to remove the root ball. We sell the latter. People want them. What is one to do? We also sell the former.
Some plants are more tolerant of life in a pot than others. Because we grow thousands and thousands, we know which they are. If visiting the nursery, find a plant you'd like to grow in a pot and then ask us for a realistic assessment of its chances. Don't ask us to recommend any other than the suggestions below. People don't buy what we suggest, people buy what they like and THEN we discuss suitability. It's the only way. Slow growing plants and pieces of topiary are the most likely to survive happily for any time - simply because they're not getting any bigger and therefore put little demandÂ on their finite roots. Alternately, fast growing herbaceous plants that just look good for the summer work well - Pelargoniums in terracotta pots are lovely. And Agapanthus africanus are good in pots. Being horrible to them by leaving them crammed in a pot encourages them to flower.
Feeding will be necessary. If you want it to flower, try Tomorite (tomato food) as it's designed to encourage flowering (a tomato plant that doesn't flower is a fat lot of good). Otherwise, a water soluble plant food is good. Put some in the watering can every time you water. Little and often is good.
We use a peat based compost on the nursery (it's nice and light) but for domestic use, a loam (soil) based compost works well. John Innes No 3. All available from us - needless to say.
Some interesting historical stuff : when Louise XIV was building his palace at Versailles in the middle of the 17th century, a part of his desire to demonstrate his enormous potency was being able to grow citrus trees and other exotics in the garden in this distinctly chilly corner of Northern France. His gardener was Andre Le Notre who presumably thought the King was nuts asking for such an impossibility. HoweverÂ this immensely ingenious and knowledgeable man came up with a solution that now we take for granted. Grow them in containers that have removable sides so the roots can be pruned and build 'Orangeries' to preserve them during the winter. The result were hundreds of iron and timber cubes that we now know as Versailles Pots. Except we don't. Versailles Pots nowadays are invariably just cube shaped wooden pots. They miss the point of Le Notre's invention by a hundred miles. His had the removable sides which allowed dead roots and spent compost to be removed and replaced with fresh compost. We visited the Palace around 2001 to learn more about the pots and the Head Gardener at the time (maybe still is?) Joel Cotin entertained us for the entire day with tales of these pots and the Orangeries. Using this method, he reckoned that his Palm trees (Phoenix dactylifera) had been in the same pots for at least 100 years and he had documentary proof that there had been on the premises an Orange tree in the same (admittedly huge) pot for 250 years. That would not be possible without the process of annual dead root removal and renewal of compost. Le Notre understood 1. the King gets what he wants 2. about plants and the immense unnaturalness of growing a plant in a pot. Why is this not done anymore? I pondered this for years but eventually realised. People can't be bothered. Simple as that. Crude root pruning using a tapered pot is the closest you'll get nowadays and it works well and is not difficult. While on the subject of Versailles, it was also fascinating to realise that the Palace Orangeries are little more that caves. They're built into a hill, have a tiny amount of light coming through the glazing on the huge doors and have no artificial heating. Because of their situation, the temperature never drops below about +6c and the fact it's almost pitch dark doesn't matter. It's so cold they're not photosynthesising so they just sit there like a lettuce in the fridge. We could do with a few more people like M. Le Notre. And a few less people who make pots but never speak to people who grow plants.
8.How to understand how Plants Grow : xxxxx
9.How to Control Pests & Diseases: If you run a nursery, pests and diseases are much more troublesome than if you have a garden full of plants - but there are lessons to be learned from those of us who run nurseries. The kind of intensive horticulture found in a nursery is conducive to epidemics. Masses of plants in close confinement under glass are an unnatural environment where the natural predators and conditions found in a garden are absent.
When we started the nursery, I listened to much discussion about the various pros and cons of different noxious chemical agents and the effectiveness of a newish science called 'Biological Control'. Lots of noise about all that stuff but little discussion about the benefits of merely being observant and nipping outbreaks in the bud (is that where the expression comes from?) and preventing an outbreak becoming an epidemic by reacting extremely fast. If you know your plants, you'll know what plants are susceptible to what pests and diseases so you go looking for trouble.
This propensity that certain plants have to pests and diseases can be put to very good use.
As you become more of a gardener, it becomes a habit. Some plants are at the very top of a list of 'my favourite plant' if you're a pest or a disease. For example - ifÂ I look at the young growth on the Japanese Pittosporum (Pittosporum tobira) and it doesn't have Black Fly, then I can be pretty sure we have no Black Fly on the nursery. In that case, if I did find some Black Fly on the young growth, the rapid reaction would be to cut off all the affected leaves, put them in a bag and incinerate them, immediately - NOT to wait until tomorrow (by which time an epidemic could have broken out) and then spray everything. Understanding what's likely to get what and then reacting immediately is the key. Not waiting for tomorrow or even this afternoon.
In the garden we never use insecticides and only rarely we will use fungicides for problems such as Box blight or mildew. See Biological Control (No.1) and Pests and Diseases (No. 43) in the Glossary of Terms. In the descriptions of the plants on this website, propensities to certain pests and diseases are always mentioned but here are some examples of some 'highly susceptibles' :
Red Spider Mite : Musa basjoo, Bamboo, Euphorbia mellifera / Black Fly : Young growth on Pittosporum tobira / Mealy Bug : Phormiums (all) / Green Fly : Bamboo (in early summer) / Mildew (Powdery or Downy) : Viburnum tinus, Prunus lusitanica / White Fly : Phillyrea latifolia, Melianthus major, Paulownia tomentosa / Fungal Spots : Yucca (all), Chamaerops humilis.
10.How to understand Creative Maintenance : xxxxxxx
11.How to stop worrying about Roots & Foundations : Much hysteria - mostly promoted by insurance companies - surrounds this subject. Subsidence leading to cracks in your walls can happen if the house is built on clay and we get a particularly dry summer. The clay that the house sits on will have a stable water content which allows the house to remain intact. A large tree close to a house in a dry summer might start taking water from the soil where it wouldn't normally. This means the water content of the clay is reduced, the clay shrinks, the foundations settle and cracks can appear. If cracks appear in the walls and there's a tree within 100 metres (slight exaggeration) of the house, the insurance company condemns the poor (usually innocent) thing, insists on its removal and when the cracking continues (probably because the house is on poor foundations), the insurance company shrugs its shoulders.
If the house is built on chalk, limestone or any other rock, this can't happen. Apart from anything else, if a tree's so close to the house and so big, won't the risk of it blowing over and crushing the house be a bit bigger than a few tiny cracks?
The next thing to understand is the relationship between the extent of a tree's roots and the extent of the tree's branches (and therefore its leaf area). Keep a tree's growth under control by clipping and shaping and the roots have no reason to expand beyond what is necessary. Start with a tree that can become huge (a Beech or a Holm Oak for example) and keep it clipped to a suitable size to grow near a house (or anywhere else for that matter) and you'll notice that the trunk never gets to anything like the proportions of a fully grown unclipped tree. What you won't notice (because it's underground) is that fact that the roots are doing exactly the same as the trunk - they're limited in their growth by the constant removal of leaves and the drastic reduction in photosynthesis.
A useful corollary to this argument is the whole business of keeping a plant in a pot. As we constantly point out, plants don't grow in pots (they grow in the ground) but keep a plant to a constant size by clipping (topiary) and the plant has no reason to produce as many roots as if it was left to its own devices. The finite environment of a pot will then be much more acceptable to a topiaryed plant than to a plant that is allowed to grow and grow but has nowhere to send its roots.
We once had a garden to do in a rather smart part of London on land owned by a well known Duke who shall remain nameless. We wanted to use clipped Holm Oaks (Quercus ilex) as they were highly suitable for that particular garden (they clip well and are shade tolerant which was necessary as there were large trees in the neighbouring gardens). Unfortunately we had to get permission from a horticultural apparatchik who worked for the nameless Duke. He heard the word 'Oak', thought 'Big' and 'Foundations not okay' and refused our request but allowed us to use Olives instead. When he heard Olives he thought 'Small' and 'Foundations okay'. We pleaded with this person that as the Oaks were to be clipped, the roots would never threaten the buildings. "But what if future generations fail to clip the oaks and keep them under control?" said the nameless horticultural apparatchik who worked for the nameless famous Duke. For one thing, at that address, that's not going to happen and for another thing, Olives left to their own devices become just as big as Holm Oaks but they very rarely do because they're always grown for their fruit and the branches are always cut back so the olives can be reached - that's why the apparatchik thought 'small'. Wrongly. The Olives were used but are hopelessly unsuitable because they're not tolerant of shade and they're all thick at the top and thin at the bottom and - predictably - are a disappointment to our customers and to us.
The abysmal ignorance of a 'qualified' horticulturist about 1.The relationship between plant size and root size and 2.The potential size of Olive trees, has left me still fuming after nearly 15 years. Can you tell?
12.How to stop worrying it's going to die : People often worry they're 'going to kill it' which is odd because killing a plant is a major accomplishment. Millions of years of evolution and adaptation to constant climate change has equipped all living things with a powerful survival instinct. The reason for our (all living things, that is) existence on the plant is due to our tenacity and refusal to give up.
So how would you do it? You could try planting it in a bog or water it constantly until it drowns. Or you could never water it even when it never rained. That would do the job. You could plant it in compacted clay sub-soil (always a possibility in newly built houses in central Sussex) and it might be so miserable it might as well be dead.
Death by disease in recently planted plants is incredibly unlikely. Only old plants are susceptible to fatal diseases and they need to have been in the ground for some time to be affected by a hostile pathogen in the soil. If recently planted plants are ailing, it's almost always an environmental problem brought on by poor soil and either over or under watering. Another possibility (but this will take longer to manifest itself) is a woody plant that's been planted too low; if soil accumulates round the base of some woody plants, the soil will begin to rot the bark and the necessary exchange of water and nutrients through the cambial layer (the bark) will be interrupted and can (very slowly) kill the plant.
If you need further reassurance that killing plants is extremely difficult, there's more on this subject in Frequent Questions. May I commend 5. "What if it dies?" and 6. "Why do I kill everything?" If you plough through that lot and are still convinced that killing plants is easy, may I respectfully suggest you consider a pastime other than gardening?