What End of a Flower Bulb Do You Plant Down?

Bulbs

• Tulips, daffodils and hyacinths are spring-flowering "true" bulbs. True bulbs have a layered structure, similar to an artichoke or an onion. Plant true bulbs with their flat end down and pointed end up. Plant these harbingers of spring in late autumn for flowers the following spring.

Corms

• Corms are the solid, swollen, enlarged bases of stems that typically form underground. Crocuses, anemones and gladioli grow from corms, as does the little-known vegetable kohlrabi. Plant corms with the stem end up and the portion with the roots growing out toward the bottom.

Rhizomes

• Swollen stems that grow underground in a horizontal direction, rhizomes are the bulblike roots of iris, four o'clocks ("Marvel of Peru") and both culinary and ornamental ginger. Rhizomes will typically have a stem protruding on the part that should face up, but if no such growth point is evident, plant the rhizome with the smooth side down.

Tubers

• A catch-all category, tuber refers to any bulblike underground plant part not fitting in the above categories. The edible potato is the most commonly known tuber, but ornamentals such as dahlias and gloxinia are also considered tubers. To plant, examine the tuber and orient it so the growth buds are facing up. These will appear as slight bumps on the tuber, or will resemble "eyes" on a potato.