Digging and Storing Dahlia Tubers
When is the Right Time to Dig?
You can dig your dahlias before they officially die back from the cold if need be or you can wait until sometime after the first hard frost. If you wait until the frost kills them, you might want to wait a few days up to a week after for the tubers to harden off a bit, making them less likely to break when you dig them up. On the other hand, there are often so many tubers that losing one or two is not that big a deal.
Be sure to properly label all of your dahlias before the first frost and well before you dig the tubers.
Digging the Tubers
We like to loosen the ground around the plants first with a broad fork or a digging fork - very similar to digging potatoes. You want to avoid stabbing the tubers with your digging tool, yet get close enough that the tubers come out easily, breaking as few as possible as you extract them. We typically aim for the outside of the “drip line” of the plant.
After you have loosened the the soil around the plants you can use the digging fork to dig down and under the plant so to lift it out while gripping the dahlia stalk and pulling gently. This is the tricky part. Hopefully you have some nice friable soil so that the tuber mass will pop out easily after you have loosened enough soil. Gentle is the name of the game. Once the tuber mass is out you can brush off any clumps of soil that are still clinging to the tubers, again being careful not to break tuber necks (where the tubers connect to the main stalk).
Being sure the soil is properly loosened before pulling up gently on the stalk will reduce the risk of breaking tubers.
Choosing When to Divide
Once all your tubers are dug, you can snip off the stalk and begin to pack them for winter storage. Some gardeners/farmers like to wash and divide their tubers in the fall. We like to pack them with a little soil still attached and wash and divide them in February or March. We take a loose inventory so we know how many tubers of each variety we will have to work with in the early spring. We may divide the large tuber masses a little bit just so they fit in the nursery buckets better, but you can also put the whole clump (or several) in the bucket surrounded by slightly moistened sawdust.
Packing Dahlias
We use large nursery buckets to pack our tubers because they are easy to find and come with holes in the bottom for ventilation. One could also us a Rubbermaid container. We use clean sawdust for packing. One can also use peat moss or vermiculite as a packing and storing material. We have found that in our dry rocky mountain climate it is best to slightly pre-moisten the sawdust (or whatever material you are using) before packing your tubers. Some locations may have a more humid climate and may not want to moisten the packing materials. After layering the dahlias with moistened sawdust, top off the bucket with a substantial amount of sawdust to keep the top lay of dahlias from drying out. Be sure that each tuber clump or each bucket is labeled appropriately.
Storing Dahlias
Store in a cool (37-47 degree), dark place until it’s time to divide your tubers. A crawl space, garage closet, or ideally a root cellar are great locations for storage. Check on your tubers once a month. They should stay firm and slightly moist. If you find that the sawdust or packing material is drying out, water each bucket a little with a watering can. If the tubers are getting slimy and potentially rooting, place a fan in the area that you are storing your tubers to dry things out. You may even choose to repack these tubers into fresh sawdust, though this would be a rare case.
If you have any questions don’t hesitate to contact us about dahlia digging and storage. Once your tubers are tucked away for the winter you can start dreaming of your future dahlia gardens! Dig it?
