· Brent Wilson's Answer
· Like John, I grow a lot of Japanese maples in containers on my back deck, which is partially shaded. I have several varieties that have been growing in the same pots for upwards of 8 to 10 years. Some have outlived the pots they are in! These are dwarfs with a very slow growth rate and the pots are about 18 to 24 inches or so in diameter at the top. All I do is prune the trees once a year in late winter and snip a stray branch here or there when necessary. Other faster growing varieties I've had to shift up to larger containers or transplant into the landscape. Slow growers like Red Dragon should last many many years in a container provided the container is of fairly large size. If you don't want to have to shift up to larger pots, I'd recommend sticking with varieties that are known to be slow-growers or dwarfs and start out with a large pot to begin with. I always plant some type of evergreen groundcover in the container with the Japanese maple and, during the first few years, even add in some annual flowers. Small ivies, creeping jenny, blue star creeper, low-growing sedums, and dwarf mondo grass are some of my favorite groundcovers for containers.
Here's an excellent article about growing Japanese maples in containers:http://www.gardenality.com/Articles/892/How-To-Info/Planting/Growing-Japanese-Maples-In-Containers/default.html
Much success with your Japanese maple container garden!