What are the best patio trees for containers to provide shade?
Q: What are the best patio trees for containers to provide shade? (For Denver, CO elevation and climate)?
A: When I first got out of college with my horticulture degrees in 1985, I worked part time for a German woman who was an AVID gardener. She had a fairly small garden chock-full of plants. There were numerous dwarf fruit trees and conifers in whisky barrels mounted on rollers. She potted them using one half sandy topsoil and one half outdoor potting mix. This worked quite well for the dwarf trees and bonsaied evergreens. Realize that the top-to-root ratio is very important for trees including shade trees. It’s not likely that you could get a tree to grow large enough to produce shade before its roots outgrow the pot.
If you would like to experiment, try honeylocust, Gambel’s oak, or non-dwarf fruit trees like peach or apple. You may be better off planting hardy vines like honeysuckle, silver lace vine, or woody type Clematis using large pots over 20 inches in diameter and 18 inches deep, and installing arbors that reach from one pot to the other.