Take time to label each Dahlia: name, color, variety. Carefully dig up dahlia tubersusing a digging fork after the first hard frost in fall (when the leaves turn black). Cut the stalks so they are about 8" tall from the ground.
Step 2: Let sit and de-dirt
We like to lay the tuber clumps out on newspaper in a cool spot for about 3 days or until they're fully dry. Once dry, use a small dust broom to brush off any remaining dirt.
Step 3: Start spreading the news
Wrap each (labeled!) tuber gently in dry newspaper, then pack loosely in a clean, dry cardboard box. We like to label the outside of the cardboard box with the date and the varieties inside.
Store the box in a cool, dry, *dark* space (about 50 degrees) until mid to late February.
Step 4: Unpack (label) and plant!
In mid to late February, unpack your (labeled!) tubers carefully to see which survived and which didn't. Discard any tubers that have dried up like a raisin or those that appear rotten. A healthy tuber should be firm like a potato.
Make up tags with the names of the Dahlias to stick into the pots.
Fill empty, clean grow pots with damp Pro-Mix and and sit the healthy tubers (tuber side down, stem side up) on the soil. Carefully pack more soil around the tubers up to the crown. When finished, store in a dark spot or cover with dry, clean newspaper until you see signs of life!
Step 5: Let the sunshine in
Once the Dahlias have sprouted, move to a warm, sunny spot inside your house and let them grow. Give them a few splashes of water now and then-- but not much. If over watered, months of work will be in vain.