Wait to transplant your avocado tree until danger of frost has passed in your area – typically in May. Planting pit should be 1 to 1 1/2 times the plant’s original container depth and 4-6 times the plant’s original container width in a rectilinear shape enabling the root system to go through the backfill to the corners, encouraging roots to web more quickly into the native soil. Poor draining soil is one of the most common reasons why an avocado tree or any fruit tree will not thrive. Follow the directions on the compost/humus package to add to the native soil for the backfill. Plant the tree’s rootball about 1 inch higher than the surrounding backfill to accomodate any future settling. Consult a horticulturist at your local garden center for any further directions, specifically to resolve any conditions common in your locale. Plant in full sun and also construct a watering basin about 4-6 times the plant’s original container diameter and build a berm about 4 inches. Feed with a slow release or organic fertilizer formulated for citrus/avocado and water the newly transplanted avocado thoroughly to collapse any air pockets. Make sure the tree is in full sun.