Crimson Queen is a threadleaf variety of Japanese maple, Acer palmatum dissectum, that grows naturally as a shrub but more often is shaped into a tree by removing the lower limbs. The upper limbs are drooping and the tree's feathery, bright red leaves turn deep burgundy or purple in the fall. The Crimson Queen Japanese maple reaches a height of between 6 and 10 feet and does well in United States Department of Agriculture plant hardiness zones 5 through 8.
Spread 2 to 4 inches of organic mulch around the base of the Crimson Queen maple to conserve the moisture in the soil and deter weeds. Spread the mulch in a circular pattern around the trunk, but pull it back 2 inches from the trunk to prevent disease.
Water the soil under the tree weekly until it is wet to a 10-inch depth. Place a garden hose at its base, turning it on a very slow trickle. Watch for signs of drooping leaves, which indicates the tree needs water.
Wait until the spring to apply an all-purpose, time-release fertilizer to the soil under the Crimson Queen Japanese maple. Use 1 cup of fertilizer for every inch of trunk diameter; measure the diameter by wrapping a tape measure around the base of the trunk. Spread the fertilizer from the base of the tree to 1 1/2 feet beyond the branches for young trees and 5 to 10 feet beyond the branches for large trees.
Wait until the winter to deal with any dead or diseased branches on the tree. Cut these off as closely as possible to the main trunk using a pruning saw or a pair of loppers for thinner branches. Also look for small twigs, called suckers, near the base of the trunk and prune them off with hand pruners.
Examine the tree regularly for signs of insects, especially scale insects, aphids and caterpillars, which may attack Crimson Queen Japanese maples. If insects are damaging the tree, identify the type and then spray the tree with the appropriate insecticide, or pick off the caterpillars by hand.
Examine the leaves regularly for signs of disease, including tar spot and other leaf spots and Verticillium wilt. For leaf spots, spray the leaves and trunk with a fungicide. Fungicides are not effective against verticillium wilt, as it is a soil-borne fungus.