A small genus of only about 30 species, but complemented with about 25,000 cultivars, more than enough for the average gardener! A few of these popular plants are grown by gardeners in ordinary borders. However, some dahlia addicts grow the plants in special beds where a wide range of varieties can be carefully tended.
Dahlias are tuberous-rooted perennials that are not completely hardy. They flower in late-summer and autumn and it is common practice to lift the tubors every year when they have finished flowering and overwinter them in a cool, but frost-free place and plant them out again after the frosts have passed.
The flowers come in a wide range of shapes, many of them being doubles, and colours, which are mainly variations of red, orange and yellow, with some whites. Dahlias are often grown as show blooms and cut flowers, and these are usually disbudded to provide large and more perfect blooms. All of the taller varieties are likely to need staking, but none is required for the smaller bedding varieties. Dahlias need a moist, but well-drained soil in full sun. It should be fertile with plenty of well-rotted organic matter added to it. Increase from spring cuttings.