How to store dahlias over winter
f you've been enjoying the late colour of Dahlias in the garden their days are numbered as soon as weather gets icy. Foliage will turn black and the stems start to collapse.
If you garden in a warm part of the UK and have light, free draining soil you'll probably be able to get away with keeping the tubers in the ground. But if you have heavy, wet soil and live in a cold part of Britain or you have dahlias that you really don't want to risk losing, the best way to keep them is to lift and store the tubers.
How to keep Dahlia tubers safe in the ground: Cut off the spent stems and foliage, rescue any remaining flowers for a vase if they are still flowering! Keep the tubers snug underground with a dry mulch; straw, bracken or leafmould all work well. You want a thick layer to act as an insulating blanket.
How to lift and store Dahlia tubers: Carefully lift the dahlias and shake off as much soil as possible. Cut off the stems and allow any moisture to drain out of them, laying the tubers upside down is a good way of doing this. Try to keep the finger shaped clumps intact but don't panic if a few tubers get detached. They'll still be viable plants next summer. You'll also see plenty of plump new tubers as well as the mature dahlia tubers that were originally planted.
Store the dahlia tubers in pots, trays or boxes of vermiculite; old potting compost also works well. Keep the dahlias somewhere cool but frost free and keep them barely moist to keep the tubers plump and viable until you're ready to plant them next spring and summer.