If you HAVE had a freeze:
Wait at least 1 week before you dig your dahlias. During this time the tuber skins are ripening and they are preparing
themselves for winter.
If you HAVE NOT had a freeze:
Let Mother Nature do her work and let your dahlias freeze in the garden. Don’t cut them down, leave them intact and wait for the freeze. Wait at least one week after a freeze to dig your dahlias.
Why don’t I cut them down yet?
It’s best to leave the stalk intact and do not cut down if they have not felt a freeze yet. When you cut into a dahlia stalk, you will see that the stem is hollow. If water gets into the stem and freezes, then refreezes it can damage the tubers. It’s best to leave them intact and sealed up so that doesn’t happen.
Why do I have to let them freeze first:
The challenges with dahlias is that they need to feel a freeze in order to properly end the season and cure their tubers. When we let our dahlias freeze in the fall, that tells the plant, “OK, it’s time to go to sleep for the winter.” Then the stalks turn black, the energy is returned to the tubers and the tuber skins begin to thicken as the tubers are preparing themselves for winter. It’s risky to dig your dahlias before a freeze. Dahlias dug too early have thin skins and typically do not survive the winter. They may look alright now, but usually by spring, they have shriveled to an unusable tuber.
Do I rinse off the tubers?:
We always advise to NOT RINSE your tubers with a spray hose, just tap the dirt off. We see many websites that say to rinse your tubers and we do not agree. Rinsing makes it incredibly difficult to get them dry enough for winter storage, which is a key factor in getting your dahlias to survive winter storage. If they are wet, they will rot ! And there is no saving a rotten tuber.
Some parts of the country have received the first freeze, while in other parts of the country or the state, the freeze has not arrived yet. We experience this with both our farms. Our Central Washington farm in Thorp got it’s first killing frost on October 12, and we’re going to begin the harvest there this week. Our Western Washington farm 30 miles east of Seattle, has a much milder climate and is still blooming, although the flowers are looking really tired. We’re just waiting for a freeze to harvest here in North Bend.
Winter Dahlia Storage
There are many different ways to store your dahlias.
The most important tips are:
Make sure they freeze in the garden.
Once dug up, make sure they never freeze wherever they are stored. An attached garage is usually pretty safe. Unheated outbuildings typically will freeze and wouldn’t be a good choice for storage.
Make sure they are dry before they go into storage.
Storage options are:
Store in clump form or divided loose in paper bags or cardboard boxes lined with newspaper in warmer, more humid climates.
Colder Climates – usually need added protection when storing. If you want to use the cardboard box lined with newspaper method, add a layer of peat moss, add a layer of dahlias, another layer of peat moss, etc until the box is full. This can give you an added layer of protection from freezing and keeps humidity higher.
Keep the temperature at 40-50 degrees at all times during winter storage. The humidity should be kept medium-high to keep tubers from drying and shriveling. Check your tubers monthly during winter storage. See our ‘Dahlia Care’ page for more detailed information.
We recommend that you divide your dahlia tubers at some point during the winter. Here is a helpful video created by us to help you with dividing your dahlias: