Digging and Storing Dahlias for Winter

Now that your dahlias are done blooming for the season, it’s time for their winter rest and time to determine whether you’ll dig up your dahlia tubers OR to mulch them and leave them in the ground for the winter.

When do I dig up my dahlias:

Wait until your dahlia foliage looks like this before digging in the fall

Dig up your dahlias AFTER you have had a freeze.  Let them freeze in the garden, and wait about 1-2 weeks after a freeze to dig them up.  During this time, the skins are thickening up underground and they are preparing themselves for winter.  Dahlias dug before this time or too early, generally will shrivel and will not survive winter storage.

By mid November, if you live in an area that DOES NOT freeze, it is safe to dig up your dahlias by mid November.

Do I really have to dig up my dahlias?:

We always recommend that you dig your dahlias every fall for a few reasons.

1 – Dahlias are tender and will not survive harsh, freezing winters with frozen soil.

2 – Digging and dividing your dahlias over winter will keep your dahlias healthier and stronger than the ones left in the ground.  Dahlias left in the ground year after year, will create a massive tuber clump that will send up many week, unproductive stalks.

3 – It’s a chance to save your favorite dahlias and build your stock up!

If you live in an area that does NOT have harsh, freezing winters you may be able to leave your dahlias in the ground.  In mid November, cut the stalks down low enough to the ground to where the stalk is not hollow.  This will keep the water from getting into the hollow stalk and freezing, and re-freezing your dahlias.  Add a THICK layer 8″ – 12″ of mulch such as straw, grass clippings, leaves or compost to insulate the ground.  Remove the mulch in March so the soil can begin to warm up.

If you only have a few dahlias in your garden, and you don’t want to go through the work of digging and storing.  Leave them in the ground, if they come back GREAT! If they don’t, oh well just pick up a few new tubers in the spring.

 Digging Dahlias:

 Use a digging fork, pitch fork, shovel, whatever works best for you.  Start back about 12″ from the stalk and start to dig, working your way around, get under the dahlia

Digging Dahlias

clump and lift up.  Tap off the dirt with your shovel, do not rinse your dahlias.  We find that it’s rinsed tubers sometimes have a tendency to shrivel in winter storage and it’s extremely difficult to get them dry enough before storing for winter.  If your dahlia tubers are wet, they will rot and there is no saving a rotten tuber.  Cut the stalk off at this time, and get them to an area that is above freezing.  Think about where to store them that stays in the 40-50 degree range.

Should I rinse my dahlias after digging:

We say NO to rinsing, tap the dirt off.  If there is still lots of dirt after tapping, set the clump aside for a few days to let it dry out.  Tap again, and most of the soil will come off.  It is OK if there is a little dirt on the clump, it keeps a little insulation and humidity by the clump.  When you rinse, it’s so difficult to get them dry enough before going into storage.  Keeping them as dry as possible after harvest, will bring you more success.

Winter Dahlia Storage

Freshly dug dahlia tubers

There are many different ways to store your dahlias.

The most important tips are:

1. The ideal temperature is around 40-50 degrees. An attached garage is usually safe.  Unheated outbuildings typically will freeze and aren’t a good choice for storage.

2. Once dug up, make sure they never freeze wherever they are stored.

3. Make sure they are very dry before they go into storage.  Tap the dirt off the clump, do not rinse.

Do I divide in the fall or the spring?:

Either one is fine, in the fall they are easier to cut, in the spring the eyes may be easier to see, but they will be tougher and harder to cut.  We start dividing in the fall and continue through late February.

Storage options are:

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.

If you want to store your dahlias while they are still in clumps, you can use this method too.  Layer of peat moss, layer of dahlias in clumps, peat moss, etc.

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.

Dividing Dahlias:

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:

Our website is OPEN for dahlia tuber sales.  You’ll get the best selection when you order now for Spring 2019 shipping or farm pick up!

We hope this blog post helps you have a successful dahlia harvest!

Happy Harvesting from Dahlia Barn!

And a few pictures to remember why we love dahlias so much