Sexual propagation involves the union of the pollen (male) with the egg (female) to produce a seed. The seed is made up of three main parts: the outer seed coat, which protects the seed; a food reserve (e.g., the endosperm); and the embryo, which is the young plant itself. When a seed is mature and put in a favorable environment, it will germinate, or begin active growth. In the following section, seed germination and transplanting of seedswill be discussed.

Asexual propagation is the best way to maintain some species, particularly an individual that best represents that species. Clones are groups of plants that are identical to their one parent and that can only be propagated asexually.

Annual flowers live only for one growing season, during which they grow, flower, and produce seed, thereby completing their life cycle. Annuals must be set out or seeded every year since they don’t persist. Some varieties will self-sow, or naturally reseed themselves.

“Bulbs” is a term loosely used to include corms, tubers, tuberous roots, and rhizomes as well as true bulbs. This publication will refer to all of the above as bulbs. Many vegetables are propagated from or produce edible organs of these types (e.g., tuber, Irish potato; tuberous root, sweet potato; rhizome, Jerusalem artichoke; bulb, onion).