Azalea japonica - various
Slow growing, evergreen, very colourful and quite particular about soil. They like the acid peaty soil you get a lot on the Sussex and Kent high Weald (the high bit in the middle). If you have that sort of soil, they love it so much, you should indulge yourself.
It's naturally quite moundy in the way it grows (rarely more than 5ft high) and therefore lends itself either to being clipped into contiguous blobs (or karikomi as the Japanese call it) or shapely little trees - almost like big bonsai or small niwaki. We're getting very Japanese in our terminology here but then in Japan they're everywhere. I'd always understood that the word karikomi referred specifically to the Japanese habit of clipping into contiguous mounds (or blobs as we usually say). I was then rather disappointed to discover it just meant cut so the word's just as likely to be used for a haircut as for pruning azaleas.
By now you won't be surprised to hear that they're native to Japan (the specific name 'japonica' is a clue). They come in dark red, pink, white and purple. We try to stick to the dark red and white but occasionally, we stray and have other colours. They flower in spring so if you're going to shape them (always recommended) do it during the summer after flowering - unless you don't want the flowers in which case you could do it earlier. The more you clip them, the tighter they become and the nicer they look.
Acid, organic soil in full sun or light shade.
Propagated by cuttings.