Garden tip: The different types of bulbs

Do you know the difference between a bulb, rhizome and tuber? “Sunset Western Garden Book” explains that there are five types of bulbs: true bulbs, corms, rhizomes, tubers and tuberous roots. Bulbs include the flowers we’re so familiar with — daffodils (Narcissus), tulips and lilies. Most true bulbs have scales and a protective papery outer skin and produce offsets.

A corm is a solid stem base, not scales. Common plants are crocus and freesia.

A rhizome is a thickened stem. Irises may be from bulbs or rhizomes.

Tubers are underground stem bases. Cyclamen and begonias are examples. (Some begonias are from rhizomes.)

Tuberous roots are thickened roots to store nutrients. The diversity and beauty of dahlia flowers make them popular with gardeners.

In my garden, I have daffodils growing, grape hyacinths poking up, tulips in 14-inch containers, a bed of native Douglas iris and the horticultural peach beauty, Dutch iris. What kinds of bulbs do you have?