Ranunculus are those stunning spring blooms that get all their energy from underground tubers. But here’s the catch: those tubers are usually pretty sensitive and don’t play well with frost. If you want to keep your ranunculus coming back year after year, you’ve got to make sure they stay cozy and frost-free through the winter.
Are Ranunculus Winter-Hardy?
By the time fall rolls around, the ranunculus season is winding down, and the plants retreat into their tubers for some well-deserved rest. Once the foliage has withered, you’ll want to cut it back close to the ground. To make sure these beauties pop up again next year, it’s important to know just how much cold they can handle. While a few specific varieties can survive temperatures down to 14°F (-10°C), most will turn to mush if it hits 26°F (-3°C).
In very mild regions, you might get away with leaving them in the ground if you provide a thick “blanket” of mulch, brushwood, or compost. However, potted ranunculus should always be moved indoors; pots freeze through much faster than the ground, which is a death sentence for the tubers. The safest bet? Dig them up. Here’s how to do it:
- Carefully lift the tubers out of the soil in late fall (before the first frost hits).
- Gently brush off any loose dirt.
- Let the tubers air-dry for a day or two.
- Store them in a box lined with several layers of paper towels or wood wool.
- Keep them in a spot that is dry, cool (around 43-46°F), and dark—like a basement or a garage.
You can also wrap them in newspaper or tuck them into a pot of dry soil for the winter. Taking these extra steps is a must for young tubers, plants in colder climates, or anything grown in containers.
Timing Your Winter Storage and Replanting
In the fall, the top part of the plant will die back. Once the leaves and flowers have faded and you’ve trimmed the remains, it’s time (usually mid-to-late October) to move those tubers into storage. You can plan to bring them out of “hibernation” the following March. Before you put them back in the dirt, give the tubers a good soak in cold water for about 5 hours so they can plump up. Then, plant them about 2 inches deep in fresh potting soil. Once late April arrives and the threat of hard frost has passed, they’re ready to head back out into the garden.
One cool thing about ranunculus is that they grow “baby” bulbs (offsets) on the main tuber during the growing season. Before you put the tubers away for winter, you can gently detach these little guys and store them separately. Come spring, plant them just like the others, and they’ll grow into brand-new plants!
