Repeat performance
Dahlias are tender, so in our gardens, which are not just cold but also wet in winter, they are best lifted and stored. Dig them up promptly after the first frost. Be sure to get right under the tubers so you don’t split them. Shake or brush off the excess soil, cut back the stems almost to the roots, and invert the whole caboodle to allow excess moisture to drain away, before immersing them in their winter plunge of dry compost, chipped bark or shredded paper and storing them in a frost-free place. They can be stored upside down, too, but must be turned the right way up before they start to grow in the spring. In February or March, pot them up in loam-based compost and gradually bring them into growth by watering, then plant out into the garden only after all risk of frost has passed. If you’re in a warm part of the country and have free-draining soil, a lower maintenance option is to leave dahlias in the ground over winter – though this can result in the plants putting on a less impressive show. Cut stems to the ground after the first frost and then pile up soil above the tubers to prevent them from freezing – this can give the impression that enormous moles have been at work!