"Liners" is a horticultural term referring to trays of very young plants, usually grown for sale to retailers or wholesalers, who then grow them to a larger size before selling them to consumers. Liners are usually grown from seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

, but may also be grown from cuttings or tissue culture

Tissue culture

Tissue culture is the growth of tissues or cells separate from the organism. This is typically facilitated via use of a liquid, semi-solid, or solid growth medium, such as broth or agar...

. They are grown in plastic trays with many "cells," each of which contains a single liner plant.

External links

• USDA Rules defining liners