GardenBanter.co.uk

In article , Bob Hobden
writes

"Alan Holmes wrote ...

How to store tubers overwinter?

Any expert out there who knows?(:-)

Whilst I usually leave them in, when I have dug them up I store in
Multipurpose potting compost ('cause it's handy). Don't forget to stand them
upside down for a while so the hollow stems empty of liquid and dry out .
When the shoots start to appear in the spring either plant the tubers out or
if you want to increase your stock, take some cuttings and plant the tubers
later.

Not sure if he'll reply himself but this is what David Hill says on his
web site:
http://www.abacus-nurseries.co.uk/

Lifting and Storing Tubers
It is best to leave the plants in until the first frost has cut down the
plants. Cut back the stems to 4 or 5 inches above the tubers, then lift
the tubers and clean the soil off them, taking care to label each plant.
Remove the thin, fibrous roots and treat with a fungicide and leave them
upside down to dry. When they are dry, store them in a dry frost-free
place until you want them to produce cuttings for next year or, if you
want to plant them directly out.

Planting Out
Plant firmly and water the plant in. It is a good idea to put a cane in
for the plant at this stage, as this way you will do no harm to the
roots. Be sure to keep the plants watered in dry weather. A balanced
liquid feed can be applied at fortnightly intervals starting about 3
weeks after planting out and continued until the plants are flowering.
You can then change to a feed with a higher potash level as this will
improve the quality of the flowers.

There's more advice on the Dahlia society page

http://www.dahlia-nds.co.uk/web2d.htm
They also add .......................
Tip 1 - Do not wait until frost kills the stem before digging - dig once
foliage has been killed by frost
Tip 2 - store tubers under green house bench directly with contact with
soil either encased in soil (as dug) or washed
Tip - 3 - cover Dahlia tubers with either, fleece, old blankets or straw
to stop frost

--
Janet Tweedy
Dalmatian Telegraph
http://www.lancedal.demon.co.uk