Written by Hailey Farrar
Did you know one single dahlia plant can produce 5-20 tubers by the end of the growing season? A tuber is a type of enlarged structure that plants use as a storage organ for nutrients, serving as a food reserve and bearing buds from which new plants will grow. These tubers can then be dug up, divided, and stored away until the next growing season. This post will help you identify when to dig up your tubers, understand tuber anatomy, learn how to divide them, and store them.
Once the foliage of your dahlias has died back, it is time to dig up the tubers. This is usually after the first frost in late October. Cut back the dead stems, leaving 2-4 inches of the stem above the ground. When starting to dig up the tubers, you want to make sure you dig about 6-8 inches away from that stem so as not to damage the tubers.
After removing most of the soil and trimming the fibrous roots, you can start dividing! When you’re ready, grab your plant shears and begin dividing the tubers! Take a look at your bundle of tubers and notice how all the individual tubers have a large body and a thin neck that leads to a crown. The crown is where you’ll find the eyes, which is where new growth will come out. Take your shears and cut between the crown and the stem, making sure not to cut through or cut off an eye.
If you are dividing multiple varieties of dahlias, I like to write the variety on the tuber with Sharpie, but you can also label different boxes for different varieties.
Once you have divided all of your tubers you’ll want to store them in a cool dry place like a garage or unheated basement and pack them with a substrate like wood shavings, peat moss or shredded paper. This helps prevent shriveling, but be sure to check them regularly for signs of rot as well. If you do encounter any rotting tubers be sure to remove them immediately so it does not spread to others.
Dividing and storing dahlia tubers might seem intimidating at first, but with a bit of practice, it becomes a simple and rewarding part of your gardening routine. By taking the time to dig, divide, and store your tubers properly, you’re setting yourself up for an even more vibrant and abundant garden next year.
Whether you’re growing dahlias for their stunning blooms, sentimental value, or simply the joy of gardening, saving your tubers ensures your favorites come back season after season stronger and more beautiful each time.
