Brighten Your Winters and Reawaken Your Garden with These Tried-and-True Overwintering Canna Survival Strategies
For Canadian gardeners in zones 3 and 4, the lush, flamboyant blooms and bold foliage of Canna lilies bring a touch of the tropics to even the briefest summer.
But as autumn’s crisp air signals the coming chill, a new question arises: How do we preserve these tender beauties when our winters can easily plunge below -30°C?
Yet, with a bit of planning and care, your Cannas can become a cherished part of your garden for years to come.
In this blog, we’ll explore three ways to overwinter canna lilies, including keeping them as houseplants and saving their rhizomes, with step-by-step canna overwintering instructions and inspiration to keep your garden dreams alive all year long.
Why Should I Overwinter Canna Lilies?
In zones 3 and 4, winter temperatures routinely drop far below freezing. Unlike hardy perennials, Cannas are native to subtropical and tropical regions, and their rhizomes simply won’t survive if left in the ground.
Overwintering is not just a practical necessity; it’s a gardener’s act of optimism, a way to ensure the drama of Cannas returns to your garden every summer, bigger and bolder than before, while also saving you money for the next gardening season!
It’s best to start planning for overwintering Cannas in late summer or early fall, before the first frost. Planning your overwintering prep early gives you time to prepare your plants and space, ensuring a smooth transition into the winter months.
The overwintering tropical plants option that is best for you depends on how much space you have available and whether it is a warm space or a cool space.
See Also: How to Prepare Your Garden for Winter
Canna Lily Overwintering Option 1: Keep Cannas as Houseplants Through the Winter
One of the most delightful ways to keep your Cannas thriving during the winter is to bring them indoors as houseplants.
This method not only preserves your canna lilies but also fills your home with vibrant foliage and, with luck, the occasional bloom during the darkest months.
A Step-by-Step Guide to Indoor Canna Lily Care in the Winter Months
- Choose the Right Plant: If you have Cannas growing in pots outdoors, these are the easiest to transition inside. If your Cannas are in the ground, carefully dig up a few healthy specimens before the first frost.
- Potting Up Cannas: If the Canna rhizomes are being dug out of the ground, select a container that is large enough and has drainage holes. Use a high-quality potting mix, position the rhizome slightly below the soil surface, and water thoroughly once it’s in place.
- Acclimate Cannas Gradually: Before bringing your Canna indoors, place it in a shaded, protected area for a few days to help it adjust to indoor conditions from outdoor conditions.
- Find the Perfect Spot for You Cannas: Cannas crave sunlight. Place your potted Canna near the brightest window you have, ideally a south-facing one. In the low-light days of a Canadian winter, overwintered canna lilies can be supplemented with a grow light.
- Water and Humidity for Cannas: Keep the soil lightly moist, but never soggy! Cannas appreciate higher humidity, so you can mist the leaves weekly or biweekly, or place a tray of water nearby.
- Fertilizing Cannas during the Winter: During the winter months, Cannas, alongside all other tropical plants, are basically in a holding pattern from November to March because of the reduced sunlight our climate receives, so there is no need to fertilize them until they begin to grow actively in March or April. If you notice the leaves are looking pale, you may spray them with a very dilute fertilizer solution.
- Pest Patrol for Cannas: Monitor your Cannas for common indoor pests, such as spider mites and aphids. If you spot any, treat them promptly with insecticidal soap or wipe them off with a damp cloth.
If you notice any other issues such as yellowing leaves or stunted growth, it could be a sign of overwatering or nutrient deficiency. Adjust your care routine accordingly.
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By overwintering Cannas as a houseplant, you’ll enjoy lush greenery and even a chance at winter blooms, making your indoor space a living reminder of the coming garden season.
Canna Lily Overwintering Option 2: Keeping the Canna Dormant in the Original Pot
While bringing a Canna lilies indoors as a houseplant is a great way to keep them growing and to let the rhizomes be undisturbed over the winter, not everyone has the room to accommodate them.
But if you have space in a cool area, there’s another way you can still keep the roots intact and untroubled – Cannas can be kept in their original pot, or settled in a smaller pot if you break off some soil.
A Step by Step Guide to Overwintering Dormant Canna Lilies
- After a Light Frost, Cut Down the Plant Stalks: For this option, wait until a light frost has killed the foliage and trim the Canna stalks to 7-10 cm (3-4 inches) above the soil. Allowing the foliage to freeze lightly signals them to enter dormancy.
- Where to Store the Canna Pot: Place the Canna pot in a dark, cool (5-10° C /41-50°F), dry place like a cold room, a root cellar (some people still have them & I’m jealous), a heated garage, a cool greenhouse, or a cool dark spot in the basement.
- Ensuring Rhizome Hydration: Give the Canna lily a slight drink of water as you let it go dormant. Cover the pot with a breathable fabric, such as burlap, and check it every month to assess its hydration. If the soil is parched, supplement it with a bit of water to keep the roots from becoming completely desiccated. If the soil is moist, let it be, and don’t add more moisture. Keeping Canna rhizomes hydrated is a delicate balance between dehydration and mold development.
- Reviving the Canna Rhizomes: In the middle of March, or earlier, if you wish, bring the potted Canna into a warmer area and expose it to sunlight and check the health of the rhizome. Healthy rhizomes are firm with intact skin and should not have wrinkly skin. Wrinkling is a sign of dehydration. Give the rhizome a little water, and it should start growing new shoots within 3 weeks to a month.
Canna Lily Overwintering Option 3: Storing Canna Rhizomes
When neither of the above Canna lily overwintering strategies is an option for you and your available space, rhizomes can be removed from the soil and kept through the winter months.
This technique is simple, reliable, and well-suited for gardeners with limited indoor space.
A Step-by-Step Guide to Rhizome Storage Over Winter
1. Dig Up Canna Rhizomes After a Light Frost: Wait until the first light frost has blackened the foliage, but before a hard freeze, and cut stems back to about 10-15 cm (4-6 inches) from the base and gently dig up the rhizomes, being careful not to damage them. The light frost signals the Canna rhizome to go into dormancy.
2. Clean and Dry the Canna Rhizomes: Shake off excess soil; there is no need to wash them unless they are very muddy. Allow the rhizomes to air dry in a cool, shady place for a day or two to prevent the development of rot during storage.
3. Wait to Divide Canna Rhizomes Until Spring: If your clump is large, it is best to wait until spring to cut or gently break apart the rhizomes because the open wound on the rhizome can become a vector for disease, or it can cause the rhizome to dehydrate quickly.
4. Canna Storage Setup: Rhizomes store best in breathable materials like a cardboard box, basket, or paper bag. Avoid using plastic containers because they don’t breathe and can hold more moisture than desired.
Place a small amount of slightly damp soil, peat moss, or wood shavings—anything that keeps them somewhat hydrated but not bone-dry—at the base of your container, and position the rhizome on top. Surround the rhizome with your hydrating material until they are completely covered. It is a delicate balance to keep Canna rhizomes hydrated. Too much moisture can cause root rot, and too little can cause a loss of their vitality.
5. Storage Temperature and Humidity for Cannas: Store the Canna rhizomes in a cool, dark place, such as a basement, crawlspace, or unheated closet, ideally between 5-10°C/ 45-50°F. Check the rhizomes monthly and discard any that show signs of rot or shrivelling. Lightly mist the soil if the soil appears too dry or if the skin is wrinkling.
6. Replant Canna Rhizomes in the Spring: To give Cannas a kick start, the rhizomes may be potted up in March and grown indoors.
Healthy Canna rhizomes will be firm to the touch with intact skin, similar to a potato. A rotted rhizome will feel squishy and could possibly ooze. Wrinkled skin is a sign of dehydration. Replant the rhizomes 2.5-5 cm (1-2 inches) below the soil using a high-quality, well-draining potting soil. The stalks should be poking out above the soil, and they can be trimmed back to about 5 cm (2 inches).
Water Canna rhizomes sparingly at first to avoid root rot. If the Cannas are well-hydrated, they will have the moisture and nutrients available in the rhizome to support initial growth. Sprouting should occur within a month, but if, after about 6-8 weeks, you are not seeing any growth at all, the rhizome is likely dead.
This method is tried and true, allowing you to save multiple Cannas easily, expand your collection, or even share with friends and neighbours.
Bringing Sunshine Through the Snowy Times By Successfully Overwintering Canna Lilies
Successfully overwintering canna lilies in cold zones 3 and 4 is more than just plant care it is an act of hope that carries the exuberance of summer right through the long Canadian winter.
Whether you nurture a potted canna by your window or tuck away rhizomes until spring you are building a living bridge from one gorgeous growing season to the next. Now that you have three proven strategies to overwinter canna lilies do not let winter claim your tropical beauties.
Ready to get your whole garden ready for the big chill! Explore our complete collection of seasonal guides below for more winter prep checklists, tips on storing tender bulbs, and all the information you need to keep your garden thriving!
When the snow finally melts and your Cannas burst forth anew you will know the effort was absolutely worth it.
More to Explore for Overwintering Garden Plants
- How to Prepare and Store Dahlia Tubers Over Winter for a Flourishing Spring
- How to Put Away Hoses and Rain Barrels in the Fall
- How to Prepare Your Garden for Winter
- How to Prepare Perennials for Winter
- Three Versatile Fall Garden Cleanup Strategies
© Sharon Wallish Murphy © Gardening with Sharon
