Why I Don’t Usually Keep the Mother Tuber

I had a question recently about why I don’t keep the mother tuber when I’m dividing dahlias. In this video, you can’t immediately tell anything is wrong, but once I cut it open, the reason became clear.

Mother tubers spend the entire season in the ground, which means they’re often worn out, soft, or beginning to rot. In this case, the end of the tuber felt a little “off,” almost crispy, so I decided to check. Inside, it was already starting to rot. Keeping a tuber like this in storage can cause the entire clump to rot, so it’s not worth the risk.

Every once in a while, if the mother tuber looks really solid, I’ll keep it. But most of the time, they just aren’t reliable. If your plant didn’t produce other tubers and you need to try saving the mother, you can cut the end to inspect the interior—sometimes part of it is still usable. Dahlias don’t need the full tuber to grow, just a viable portion with an eye.

In this case, though? Definitely a “no.” I’ll trim away the bad sections and store the healthy tubers that formed, but the mother tuber itself isn’t worth keeping.