To overwinter canna lilies in Zone 5, there are a few steps you can take to ensure their survival and successful growth in the following seasons. As an experienced gardener, I have personally tried and tested these methods and found them to be effective.
1. Digging up the rhizomes: As the weather starts to cool in late fall, it’s time to prepare the canna lilies for winter. Carefully dig up the rhizomes using a garden fork or shovel, being cautious not to damage them. Shake off any excess soil gently, but avoid washing them as moisture can lead to rot.
2. Cleaning and drying: Once the rhizomes are removed from the ground, inspect them for any signs of damage or disease. Cut off any dead or decaying parts, leaving only healthy sections. I find it helpful to rinse them briefly with a gentle stream of water to remove any clinging dirt. Afterward, let them air dry for a few days in a warm and well-ventilated area.
3. Preparing for storage: Wrap each rhizome individually in newspaper or place them in separate paper bags. This step helps to prevent moisture build-up and rot. I usually add a small amount of dry growing medium, like peat moss or vermiculite, to absorb any excess moisture that may be present. This also provides some insulation during storage.
4. Storage conditions: Choose a dry and cool location for storing the wrapped rhizomes. Ideally, the temperature should remain above 40ºF (4ºC) to prevent freezing and below 60ºF (15ºC) to avoid premature sprouting. A dark area, such as a basement or garage, works well for this purpose. Make sure the storage area is free from pests or rodents that may damage or eat the rhizomes.
5. Monitoring: While in storage, periodically check the rhizomes for any signs of mold, rot, or drying out. If you notice any issues, make necessary adjustments, such as adding more dry medium or adjusting the storage temperature. It’s essential to maintain a stable environment to ensure the rhizomes remain healthy until spring.
6. Spring preparation: As winter comes to an end and the frost danger subsides, it’s time to prepare the canna lilies for planting again. Around early spring, usually a few weeks before the last expected frost, remove the rhizomes from storage and unwrap them. Inspect each rhizome again, discarding any that appear damaged or diseased.
7. Starting anew: Before planting, it can be beneficial to soak the rhizomes for a few hours in warm water to rehydrate them. This step helps stimulate growth and ensures they are ready to sprout. Once soaked, plant the rhizomes in well-draining soil, burying them about 4-6 inches deep. Choose a sunny location and water regularly to promote healthy growth.
Remember, each canna lily rhizome should be stored separately, as they should not touch each other to prevent the spread of disease or rot. By following these steps, you can successfully overwinter canna lilies in Zone 5 and enjoy their vibrant blooms year after year.