Propagation and rootstocks.

Avocado is usually treated with a special technique to assist its sprouting process.

A young avocado sprout
While an avocado propagated by seed can bear fruit, it takes roughly four to six years to do so, and the offspring is unlikely to resemble the parent cultivar in fruit quality. Rootstocks are propagated by seed (seedling rootstocks) and also layering (clonal rootstocks). After about a year of growing in a greenhouse, the young plants are ready to be grafted. Terminal and lateral grafting is normally used. The scion cultivar grows for another 6–12 months before the tree is ready to be sold. Clonal rootstocks have been selected for specific soil and disease conditions, such as poor soil aeration or resistance to the soil-borne disease (root rot) caused by Phytophthora.

Growing indoors
Often, avocados are grown from pits indoors. The pit is then stabbed with three or four tooth picks, about one third of the way up. The pit is placed in a jar or vase with tepid water. In four to six weeks, it should split and out should come roots and a sprout. If there is no change by this time, the avocado pit is discarded. Once the stem has grown a few inches, it is placed in a pot with soil. It should be watered every few days. Avocados have been known to grow large, so owners must be ready to repot the plant several times.

a houseplant

An avocado tree as a houseplant
While not particularly popular, the avocado tree can be grown domestically and used as a (decorative) houseplant. The pit germinates in normal soil conditions or partially submerged in a container of water. In the latter method, the pit sprouts in four to six weeks, at which time it is planted in fertile soil such as potting soil. The plant generally grows large enough to be prunable; however, it does not bear fruit unless it has ample sunlight. Home gardeners can graft a branch from a fruit-bearing plant to speed maturity, which typically takes four to six years to bear fruit. To obtain fresh avocado produce, however, more than one tree must be cultivated for crosspollination