Most cultivated plants produce seed in large quantities and, if this seed is collected and stored in the right conditions, it will germinate and give rise to another generation of plants.

The most common method of raising plants is by seed, but there are other methods that are equally successful. Many plants can produce a new stem and flowers from a portion of their root-stock by vegetative reproduction under the right conditions.

Dahlias are good examples of vegetative reproduction. Each year their underground stems swell to form tubers and, when sufficient food has been accumulated in these tubers, the aboveground parts of the plants die. If the tubers are examined it will be found that they are true stems and mass storage places of starch. If placed in the soil the following spring the tuber will produce both shoots and roots and, in time, a completely new plant will be formed.

When shoots or short stems are removed from some plants, and then very soon after placed in a suitable soil or rooting mixture, that portion below the soil level will form adventitious roots.

It is remarkable that stems, whose primary purpose is to bear foliage and flowers, can suddenly begin to grow roots. Roots can be formed when either end of the cutting or shoot is placed in the soil, but the best roots appear on the end which was nearest the roots of the parent plant.

Much horticultural material is produced vegetatively. Many grasses used for making new lawns and bowling-greens are poor
seeders, so you must rely on planted portions of the grasses (runners).

There are two simple ways to propagate garden plants. You can take "cuttings" or "slips" from a growing plant, or "layer" portions, usually shoots, into the soil. Shrubs and trees are propagated by either "budding" or "grafting".