Putting the Dahlias Away for Winter

The Dahlias bloomed so well this summer that I didn’t want to dig them up for winter storage. If I want them to survive for next year, it’s always best to dig them up. That way I can see how large the tubers are getting and if they have any pests or disease. It also lets me divide the tubers and plan where to place them next year. I may not want them in the same place as this year.

Dahlia Mango Sunset

I use a pitchfork and carefully dig around the base of the pant. I find by using a pitchfork I don’t slice through the tubers like I could with a shovel. I just pry the soil a bit and gently lift the whole tuberous clump out of the ground. The first thing you have to do is shake off as much soil as you can. I cut the foliage off the plant and add it to my compost bin. Once you have just the clump of tubers in your hand, place them in a sunny spot to dry out for the day. This will dry up any remaining soil clinging to the tubers. Once they are dry, shake the soil off again. You want to remove as much as you can. Check carefully with your fingers between each tuber to dislodge those stubborn soil clumps.

Overwintering dahlias

Once your Dahlia tubers are ready for storage you may want to tag them so you know which ones you are saving. Above I used a plant tag cut from a yogurt container and wrote the name of the variety on it. I used a one-holed punch to make a hole and threaded a string through to hold the tag on. Just tie the tag to the end of the stems that are left.

How to overwinter dahlias

Be sure to cut back the stems on your Dahlias. They are only going to die back and you don’t need any rotting greens in your storage box. If you look at the photo above, this is not how you want to store them. There is too much stem left on the tubers.

How to overwinter dahlias

I like to cut the stems down to about an inch from the tuber. This is when you will add your tag. Now your dahlia tubers are ready for their winter home.

How to overwinter dahlias

I use a cardboard box for storing my tubers. I place a few labelled Dahlia tubers in the box and cover them with peat moss. Note that I leave them spread apart in the box. If one does rot by chance, I don’t want rot spreading to the rest. I will then add a second layer of Dahlias into the box and keep covering with peat moss.

how to overwinter dahlias

I know, this peat moss looks like a bunch of mud in this photo. It was stored in the greenhouse and got very hard and dry. Trust me, it’s a leftover bag of peat moss. I think I will be switching to horse pellets or sawdust next year. What you need is a medium that can keep the tubers moist and stop them from drying out. You want to reach a happy medium, one that stores the tubers without leaving them too damp or too dry.

How to overwinter dahlias

This is what you don’t want to keep. You don’t want to store any diseased looking tubers. I removed this large tuber from a clump when I saw the rot and tiny hole towards the bottom. You never know what little critter may be lurking in there. You also don’t want a rotten tuber as the rot could spread to all of them and ruin your plants for next season.

How to overwinter dahlias

I also discard the single tubers that fall off. If they don’t have a piece of stem and an eye where the new growth will come out, they most likely will not grow again.

How to overwinter dahlias

Well, the box is full of tubers and I am a bit short on peat moss but they should be okay.

How to overwinter dahlias

Place the lid on your box and label it. You will have to store your Dahlias in a cool garage that is frost-free. Check on them in about six weeks to be sure they are not drying out. In the spring I like to start my Dahlias in the greenhouse to get them off to an early start. If you want to plant them outside they can go in according to your climate. Here we can plant them in late April, early May.

Winter Care for Dahlias

Here is a teaser for next year. This is Dahlia ‘Ferncliff Duo’, a flower developed by Ferncliff Gardens.

How to overwinter Dahlias

This is Dahlia ‘Honka’ which performed so well this year. So I hope I have you thinking about Dahlias for next years garden. I know I will be ordering some more. They make such great cut flowers!