A hard frost and diggin’ up Dahlias

Tue. Oct. 15, 2019

Click below to listen to my  2 min. Garden Bite radio show: A hard frost and diggin’ up Dahlias

It’s not Winter yet, technically, but some of us have already experienced some snowflakes (snowfall!!) Hello Moorehead! And my cousin’s place on Lake Maud…


And some temperatures dipping into the 30’s and 20’s! We’ve covered tomatoes or just given up! We’ve traded out the summer annuals for mums, brought the tropicals inside or bid them adieu into the compost pile and tried to get spring bulbs in the ground before our fingers freeze.


There’s also digging OUT bulbs such as cannas and dahlias.

Monster bulb/rhizome – canna bulbs 2018

That’s gotta happen before the ground freezes. Let’s talk about what a hard frost is. Technically speaking, that’s when our temperature dips to at least 28 degrees for at least four consecutive hours or if we hit 24 degrees. Some hardy annual plants can handle a light frost, but a hard freeze will generally kill ‘em off.

The begonias did okay but the coleous are toast! 10-12-19

For those of us in zones 3 and 4, we’ve already entered frost territory. As for when the ground itself freezes, right now, we still have time to get those tender bulbs out! The National Garden Bureau has been celebrating the year of the dahlia and have tips on their winter care. When your dahlias have started to brown and die back, it’s time to lift them out of the ground.

dead dahlia foliage – photo by JerryFritzGardenDesign

Digging the tubers up is super easy. Cut foliage back, so that only a couple of inches remain above ground. Take your preferred digging shovel, for this I prefer a garden fork, and dig around the tubers, being careful not to accidentally sever the roots.

photo by NGB

Once you’ve dug the tuber up, shake the dirt off and set aside. Once they’re all out of the ground, gently rinse the dirt off.

photo by NGB

Then give them a good once over and check for rotten spots, cut those out or throw them away, depending on how much there is. It’s the same with cannas. It’s important to dry them before storage.

The key to successfully storing dahlia tubers for the winter is making sure they stay dry, have good air circulation and are in a cool, dark spot.

Be sure to click on the link to the National Garden Bureau – it will take you directly to their VERY useful information on storing dahlias… and cannas too!

Dahlia ‘Nick Senior’ by Easy to Grow Bulbs