Your dahlia tubers can be planted in the spring. All dahlias are sensitive to frost, so beware of late night frost. From late April to mid-May is a good time for planting dahlias. Prepare a large planting hole, thoroughly loosen the soil and fill the hole with fertile soil. Carefully place the tubers in the planting hole, approximately 50-60 cm apart and cover with 3-5 cm of soil. Press lightly down and water immediately. Dahlias bloom most profusely in a sunny spot.

Forcing your dahlias

It is possible to bring your dahlias into flower earlier by 'forcing' them.
Lay the dahlia tubers in moist compost from the beginning of April, at a temperature of 15-20°  C. Pot your dahlia tubers up when you see the first shoots appear and from the start of May you can gradually acclimatise them to going outdoors. Mid-May, your dahlia tubers can finally go outdoors into the garden or in pots.

Fertilise your dahlias on a monthly basis throughout the flowering period until the first frost. Deadhead the faded flowers to prolong the flowering period. Prevent the soil from drying out during dry periods. As these dahlias are fairly tall it is sometimes necessary to support their stems.

Overwintering dahlias

Dahlia tubers can easily be overwintered. If you want to do this, dig up the plants after the first night frost. Then cut all stems off 15 cm above the tuber. Attach a label with the name of the dahlia to remind yourself for the next year. Shake the soil from the dahlia tubers and place in a box with peat dust or sharp sand. Store the dahlia tubers in a frost-free area such as a garden shed or greenhouse. Next spring you can plant the dahlia tubers again and they will reward you with their wonderful flowers.

This fairly small but very diverse genus originated in Central America. It has been crossed and re-crossed, the world over and so selected that there are currently many thousands of different cultivars available. Different in height, flower colour, flower size and flower shape. This led to dahlia cultivars being under-classified into various flower shapes too.
Dahlias are classified under Compositae.