Canna (Canna indica) is far too good for a one-year guest appearance on the balcony and terrace. The lack of winter hardiness makes up for the majestic flower with a strong rhizome as an outlasting organ. These instructions explain how to skilfully overwinter Indian cane.
The tubers of the canna can be dug up in autumn for overwintering
Preparation in late autumn
Indian canna, also known as canna, is a South American perennial. In late fall, when temperatures drop below freezing, the flower retracts its aerial parts. Last flowers wither, leaves wither, shoots turn brown. This process signals that remaining nutrients are being transferred to the rhizomes as an energy reserve for the next season. Now is the best time for this preparatory work:
- In early/mid-November, cut back stems that have drawn in to 5-10 cm
- Lift the rhizome out of the substrate with a small shovel or flower claw
- Brush off sticky soil
- Rinse heavily soiled bulbs with water
- Cut off damaged, rotten-brown root strands and dried hair roots with a disinfected knife
- Dust cuts with rock dust ($14.13) or charcoal ash
A creaking sound can sometimes be heard when digging up canna bulbs. This is no cause for alarm. Keep working without worry. The creaking is caused by the numerous branches and daughter rhizomes that have formed during the summer.
Tuber hibernation in 4 steps
After the preparatory work, only 4 steps have to be completed in order to safely overwinter the cannula. This process has proven itself in practice:
Allow rhizomes to dry
Tubers tend to rot. The rhizomes come out of the soil very moist. Cleaning work and water showers also increase the level of moisture. Before wintering, you should let the tubers dry for a few days. That is how it goes:
- Place canna bulbs side by side on a wooden shelf or trellis
- Leave to dry in a shady, airy place protected from rain for 3 to 5 days
Discard canna bulbs
At the end of the drying phase, carefully inspect each rhizome. Select the best, fleshy, undamaged tubers for winter storage. Specimens with brown, soft spots are wobbly candidates with little chance of a healthy overwintering.
Determine winter quarters
All rooms in and around the house with these basic conditions are suitable as winter quarters for flower canes:
- Lighting conditions: dark
- Temperature: frost-free up to a maximum of 10° Celsius
- Humidity: dry
The narrow choice is therefore: basement, windowless garage or a dark attic.
Store flower cane rhizomes
You should not store flower canes open in the winter quarters. The rhizomes could dry out completely and die. Instead, overwinter the tubers wrapped in a protective medium that allows for regular checks. The following options are recommended:
- Wrap in newspaper
- Embedding in a wooden box with unfertilized coconut soil
- Deposit in a vat with sand, straw or wood shavings
It is important to note that flower cane rhizomes do not touch. The resulting bruises cause rot, which destroys any hope of renewed budding.
tips
Please mark each dug up tuber with a label. Next spring you will gratefully read the information you wrote down about the name, variety and flower colour. This saves you the hassle of guessing whether you are holding the rhizome of a flower cane, magic flower or dahlia.