When the first frost of autumn injures the tops, the plants should be gently lifted and the stems cut
back even with the soil. The ball of roots and clinging soil should be left intact. Place the bulbs and soil clumps in a shady, cool place that is well aerated and let the tubers cure for 2-3 weeks. Then remove soil roots and stalks. If there are any soft places in the tubers, cut them out and dust with Captan or some other
Store the tubers at 50 degrees in a cool dry place, in a protective covering of vermiculite, dry peat, sand or
Sawdust. Free ventilation is essential.
When dahlias are bitten by frost, they are ready to dig. Cut the tops back to 3-5 inches and, being careful not to damage the tubers, dug carefully with a spade or fork. Remove as much soil as can be done without injuring the roots. Cull plants at digging and save only healthy ones. Spray clumps with Daconil or Captan
and let air dry for a few hours.
Store in a cool, dry place that will not freeze. Tubers should be placed in sturdy containers packed with dry
sand, peat moss, sawdust or vermiculite if humidity is low in the storage area. If you chose to divide the tubers in fall, treat the cut surfaces with a fungicide before storage.
Check the condition of the roots several times through the winter. If they are shriveling take them out of their packing, dip in water and re-pack. If there are any rotten ones discard them. Dahlias that begin to sprout during the winter are not cool enough.