Putting cannas tubers to bed in time for winter

Susan Manzke
Canna plants before being cut down.

Last fall, I waited until after our first frost to dig up flower tubers. Cannas and dahlias do not overwinter in our cold climate and if I wanted some for the following year they had to be rescued from the ground.

The late fall day Bob and I worked in 2018, we froze our fingers. It was cold and windy. This fall I was determined to dig up our tubers before cold weather set in—the odd thing was when I told a friend that we’d be digging before frost she questioned my decision, “You don’t have to hurry,” she said. “It will be a long time before the ground freezes.”

Yes, we were a long way from frozen ground and dead tubers, but I wasn’t going to take any chances. Also, if I wanted my husband’s help, I had to choose a day where he wouldn’t freeze—Bob can’t handle any kind of cold. Just looking out the window at blowing leaves gives him chills.

Since frost hadn’t killed off the summer growth, we had to clip back the plants before we could dig. It’s amazing how large cannas can get in one growing season. Bob scooped up the discarded greens with his tractor/loader and took them to our brush pile.

I started using a shovel to locate the tubers in the soil. We didn’t have to get down on our hands and knees for this activity. The cannas had been planted in two old water troughs last spring, so they were in a raised bed. Still, getting those tubers out was work.

Bob send me to the shed for a potato fork. He said that would work better than the shovel. The fork moved the tubers from the soil a bit easier, especially since Bob took charge of the fork and did the digging.

Bob busy digging up canna tubers.

Canna tubers grew and multiplied over the summer. There were at least twice as many in the water troughs as when we started last spring. After digging out one of our two canna raised gardens, we had more than we needed for replanting in spring 2020. I was ready to stop, but Bob wanted to keep digging. He said, “Not all will survive storage, so we’ll take them all in.”

Bob was right, as usual. I also knew that if we had too many for next spring that I could give them away. That’s how I got mine after all. (Thanks, Mary)

The first season we planted cannas, I planted them into different raised beds, old tractor tires. When it came time to dig them up for winter that year, we had a terrible time. The tubers had gone under the tire rim and were almost impossible to remove from their comfy bed.

It turned into quite a struggle getting those tubers out. They were never to be planted in old tractor tires again. That’s why I decided to move them to the water trough.

Soil clung to the tubers. Bob and I were covered with it. By the end of our digging, we had four huge baskets of canna tubers, but we weren’t finished. They needed some drying.

Canna tubers on the drying racks.

Bob pulled out drying racks his dad had made years ago. The tubers went on the racks in the shed and once they are dry, they will be put in paper bags to sleep in our basement until next spring.

Dahlias were also dug from the same troughs, though not as many. A different gardening friend had given me a few dahlias this spring. My favorite grew to be as tall as the cannas and had pink/yellow flowers that were six inches across. (Thanks, Bridget)

Perennials suit me better because they don’t need to be dug up every year. For a long time, I didn’t plant cannas and dahlias because of this digging issue. I’ll continue as long as we can do it in our ‘raised’ beds.

Now it’s time to check out our potted geraniums and make sure they are all set for winter, too.

Susan and Bob Manzke, Sunnybrook Farm, N8646 Miller Rd, Seymour, WI 54165;;