I am waiting until March to move two citrus trees and a hydrangea. I would suggest waiting until it is warming up but not to hot in early spring. Try and get good margins around the rootball when digging up and water well before and after. Also its good with avocados to plant on a berm or mound opposed to burying deeply as you seemed to have learned.

I have successfully relocated small trees during the winter, but early Spring (March-April) is typically recommended. Soak the soil well before digging to minimize root damage and replant on a small berm or mound as others suggested. The roots are somewhat invasive, fragile, and shallow and can spread a considerable distance... at least as far as the drip line of the tree. Don't lift the tree by its trunk... get under it and lift the rootball.

The tree will grow in repeating flushes nearly all year, but Spring and Autumn flushes are considered the most aggressive. Protect it from frost and high winds, water it heavily but don't let it get wet feet, and you'll enjoy tasty returns.

Personally, I wouldn't plant an avocado in my yard due to its excessive leaf drop and watering requirements... but that is just my opinion.

Thank you very much for your help. I will transplant it in March then and follow your good instructions!

I suppose its too much to hope that the original poster still frequents the site 12 years later and could let me know how they get on? Hopefully successfully :)