How to Dig Dahlia Tubers

Are you new to digging dahlias? Or just need a refresher because it’s been a whole year since the last time you dug up your tubers? Follow along as we dig up the precious tuber clumps of Bloomquist Wild.

Make a Plan

It’s easy to get mixed up after you start digging everything, so go in with a good plan. First, make sure everything is labelled clearly. Then figure out your process. Some dahlia growers dig, wash, divide, and store all of the same variety and then start on the next variety. Others will want to batch their tasks, and so will do all the digging, all the washing, etc at the same time. There is no one correct way to do this, but it is important to plan before you start digging so you can keep track of the variety of each tuber.

Cut the plant a few inches above the ground

Lop off the foliage a few inches above the ground. We use big loppers for this, but we’ve heard of people carefully using an oscillating saw or an electric hedge trimmer to trim off all of the foliage.

Remove plant supports, irrigation lines, and landscape fabric

Carefully remove all of these before the next step. You may need to remove the plant supports before you chop down the foliage, depending on the type of support you used.

Dig up the tubers

For this part, we recommend using a garden fork and not a shovel. We’ve have found that the garden fork is a lot less likely to damage the tubers than a shovel. Locate the stem of the first variety you’ve planned to dig. Go out from the stem about 8 to 10 inches and stick your garden fork into the ground and gently lift it up. Hopefully your tuber clump starts to lift up and you can bend down and grab it by the stem to gently loosen it from the ground. You may need to move the garden fork and repeat this step or get a little closer to the stem to safely remove your precious clump from the ground.

Wash your tuber clump

We spray the tuber clump off with a garden hose at our wash station. This allows us to assess the health of the clump and allows us to see the clump clearly to divide it. If you’re not planning to divide it, you can skip this step if you wish.

Dry the tuber clump

If you washed your tubers, let them dry until the skins and any feeder roots are dry to the touch. On a sunny day, it might take 3-4 hours. On a sunny and windy day, it could be even faster! On a drizzly day, even under cover with a fan, it can take more than 24 hours. It just depends on the weather.

Divide the tuber clump

This step is entirely optional. Some people prefer to divide their tubers in the spring. Others like to divide them now so they’ll know how many they have when they’re dreaming of their garden over the winter. We’ve written about how to decide when to divide here. Or you could do a modified version of this, and chop the clump in half so you can get all of the dirt out of the middle and then store them like that. If you would like to divide your tubers now, check out our blog post all about dividing.

Store the dahlia tubers

Dahlias need a few key things to overwinter well. They need a space that is dark, cool (but not freezing–ideally between 40 and 50 degrees F), and where the relative humidity stays around 75%. We store our dahlia tubers in coarse pine shavings (not sawdust), which you can find at your local farm store. You’ll want to check on your tubers periodically throughout the winter to make sure they are staying cozy, but not too cozy. You can set a reminder on your phone to check them every month until the spring.

Happy digging, flower friends!

Note: You might notice that we are beginning to dig before frost. We have so much to dig that we can’t delay too long! Some gardeners believe it’s not safe to dig dahlias until after a hard frost, but as our friends in zones 9 and 10 (where it rarely frosts) can attest, and as we’ve learned after many years of extensive experiments, your tubers will keep just fine if dug before frost as long as they are properly dried and then promptly stored.