Some gardeners are reluctant to grow dahlias as they perceive them all to be loud, large and boldly colored. This actually appeals to me however the modern dahlia can also be small, delicate and softly toned. Dahlias grow from a tuber, which is a swollen stem or root which contains required nourishment. From the end of July to the first frosts Dahlias keep your garden alive with color when many other flowers are past their prime.
Usually sold in packs as bare root plants. When choosing take a good look at the dahlia tubers themselves to ensure you are buying healthy specimens. You will often see a tip of new growth on the side of the stem.
Dahlias will grow in average soil but do prefer a good rich loam. They love a sunny situation but will still do well in part shade. Plant your sprouted tubers out in late May or early June. Dormant tubers can be set out a bit earlier. Plant with the crown of the tuber 3 inches below the soil surface. If growing the taller varieties insert a stake now to a depth of 1 foot.
As your dahlia grows pinch out the tips of the main stems to increase bushiness about 3 weeks after planting. Keep well watered as the buds start to form. Mulch around the stem to help keep weeds in check but do not hoe close to the stem. Occasionally feed with an organic liquid fertilizer. Once frost has blackened the leaves, cut off the stems 6 inches above ground. Gently lift out the tubers and shake off excess soil and remove any broken roots. Partially dry by standing tubers upside down for 1 week, then lay on a bed of peat moss in a box, cover the roots with peat but not the crowns. Store dahlia tubers in a cool frost free place until spring. Do not water.
Divide your tubers about every second year. Make sure that each section has a piece of stem with swollen tubers attached.
Types of Dahlias
I think what I like best about Dahlias is their wide range of size, color and form. Dahlia flower size is from miniature to giant, plant height from bedding to tall border varieties and blooms from single to double and a multitude of color tones. To help us keep them organized they fall into several categories: Ball / Decorative / Water-Lily / Collerette / Pompon / Cactus / Semi-Cactus / Single Flowered / Anemone Flowered / Miscellaneous