A first-generation offspring of two plants of closely related species or strains. (The “F” stands for “filial.”) The resulting plants are usually more vigorous than either parent and have other qualities that are considered more desirable. However, the seeds produced by an F₁ hybrid will rarely produce plants of comparable value.

Taylor's Dictionary for Gardeners, by Frances Tenenbaum. Copyright © 1997 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.