This article discusses how to store canna bulbs for the winter. By extension, you can use this information for storing other tropical or sub-tropical plants that return annually via bulbs, tubers or rhizomes, such as elephant ear plants.
Note: The instructions supplied here can be considered the by-the-book method. Some gardeners successfully store cannas down in an unheated basement during the winter without preparing them much at all and without giving them any water all winter. If they have grown the plants in containers during the summer months, then they cut the vegetation down to soil level, leave the bulbs in their pots, and bring the latter indoors, placing them in a cool, dry, dark place.
How to Store Canna Bulbs
Canna bulbs (technically, rhizomes, but known to the general public as canna "bulbs") can be left in the ground to overwinter in planting zones 8-11. In zones colder than that, to be safe, it is best to dig and store canna bulbs at the end of fall. When winter is over, the ground has thawed, and all danger of frost has passed (late spring for most growers), you will be able to plant your canna bulbs outside again.
If you want to store away your canna using the by-the-book method, follow these instructions:
- When: Although you could dig up the rhizomes earlier, most growers wait until the cannas' foliage has been killed by frost.
- Remove any foliage—dead or alive—from the plants.
- Note: In storing canna bulbs, there is some disagreement among the experts as to whether you should remove the dirt from the bulbs or let it stay on. Hedge your bets by trying it both ways. In future years, you will have learned from your experiment which way works better for you.
- Allow the canna bulbs to dry for a few days before storing, where they will not freeze. If it is warm enough to do so outside, this is preferable to drying them inside (there is better ventilation outside).
- You will be storing the canna bulbs in a plastic bag, in which you can punch some small holes, for aeration.
- Put peat moss in the bag to retain some moisture.
- Now pack the bulbs in the peat moss, in such a way that no two of them touch.
- Store the canna bulbs in a dry, dark, cool place (around 50 degrees, give or take a few degrees).
- Periodically check during the winter to make sure the peat moss around the canna bulbs is still slightly damp (if you find it dry, use a mister to dampen it).
You might wonder why, in the above steps, mention was made of the need both for moisture and for dryness. Is that not a contradiction? Well, the point is to strive for a balance. Too much moisture will rot the canna bulbs; while not enough moisture will cause desiccation. Avoid either extreme.
Many gardeners grow specifically Tropicanna canna because they enjoy the pretty, variegated leaves (although the flowers are lovely, too). Striped in four colors, they lend the summer landscape a tropical feel. These steps will work with Tropicanna canna, and all other types of canna bulbs.