Spring
Prune Ginkgoes in the early spring when they are young to improve their branching. Later, not much pruning is needed except to keep it growing on a central leader, avoiding multiple trunks. Remove dead or diseased wood and any suckers that develop. You can remove the lower limbs if you like, but do it slowly over a period of 3 or 4 years.
Maintain a year round 2 or 3 inch layer of some organic mulch such as chopped leaves, wood chips or commercial bark product over the root zone of the tree. Never pile it up against the tree trunk.
Summer
Water newly planted trees regularly for a year or two when rainfall is unreliable
Fall
After at least six months, sprinkle some granular slow-acting fertilizer formulated for trees and shrubs on the mulch for the rain to soak in. Do this for a year or two while the roots are becoming established, then the gingko can cope on its own.
Winter
Remove any storm damaged limbs as soon as is feasible.
