How to Grow an Avocado Tree from Seed or Nursery Stock

Avocado trees (Persea americana) can be grown as outdoor fruiting trees in USDA zones 9b through 11, or as large container plants in colder climates that are moved indoors in winter. The appeal of growing avocados is real, and in the right climate the trees are productive and rewarding. Understanding the difference between seed-grown trees and grafted nursery trees is the most important piece of information for anyone setting realistic expectations.

Seed-Grown vs Grafted Trees

Seed-grown avocados are easy to sprout from the pit of a store-bought avocado: suspend the pit over water with toothpicks, roots and a shoot will emerge within a few weeks, and the seedling can be potted up into well-draining soil. The resulting tree grows vigorously, has attractive foliage, and makes a handsome houseplant. However, seed-grown avocados are unlikely to produce fruit for 10 to 15 years, if ever, and the fruit they eventually produce may be inferior to the parent variety because avocados do not grow true to type from seed.

Grafted nursery trees are produced by grafting a cutting from a known fruiting variety onto a vigorous rootstock. They begin fruiting within 3 to 4 years of planting in appropriate conditions and produce fruit identical to the parent variety. Grafted trees are the correct choice for anyone who actually wants to harvest avocados.

Growing Conditions

Avocados need full sun, excellent drainage, and frost-free conditions. They are damaged by temperatures below minus 2 degrees Celsius and killed by prolonged freezing. The roots are very sensitive to waterlogging: planting on a mound or in raised conditions, or in well-draining soil with no risk of standing water, is essential.

For container growing in colder climates, choose a dwarf or semi-dwarf grafted variety. Use a large container (at least 75 liters for a mature tree) with fast-draining potting mix, and move indoors before the first frost each autumn. Container avocados can fruit but produce less than in-ground trees in warm climates.