How to overwinter canna lilies in pots so your flowers make a big summer comeback

Love your cannas? Here's how to ensure they survive the cold winter months

Beautiful vibrant coloured Cannas
(Image credit: Getty Images)

If you're looking to learn how to overwinter canna lilies in pots, you've come to the right place –⁠ not least of all because these vibrant plants have stolen our hearts in a very big way.

With their bold leaves and showy flowers, cannas are becoming increasingly popular choices in gardens right across the UK. However, they are tender perennials, which means it's unlikely they'll survive the winter without a little helping hand. So if they're a part of your container garden ideas on our list, you'll want to know how to best look after them.

How, then, can we go about overwintering them? Especially if they're sitting pretty in pots?

How to overwinter canna lilies in pots

Overwintering is one of those eternally in-style garden trends, primarily because it a) helps us keep our favourite plants alive for longer, and b) saves us money in the long run.

There's not really a one-size-fits-all approach to it, though, which is why –⁠ if you love your cannas more than anything –⁠ you're going to need to learn how to overwinter canna lilies in pots before too long.

A close-up of a canna lily

(Image credit: Getty Images/Sergio Amiti)

'Canna lilies tend to thrive in warmer climates, so they need special care and attention to ensure they survive the colder season,' says Chris Francis, director of Hillier Nurseries & Garden Centres.

'These plants are not winter hardy so overwintering them is essential to guarantee these pretty blooms survive until next spring.'

The easiest way to overwinter your cannas, of course, is in pots and containers –⁠ which is especially handy if yours aren't sitting in your garden borders right now. 

Orange Canna lily at raining season Chiangmai Thailand.

(Image credit: Getty Images)

When it comes to how to overwinter canna lilies in pots, the process is really simple as you can leave them in their original containers. 

'As temperatures drop, keep an eye on the weather as you want to make sure you begin overwintering before the first frost in your area,' says Chris. 

'Move the potted canna lilies indoors or into a greenhouse, where the temperature will not drop below 12°C. It is essential that they remain in a place that is completely frost-free, or the cold temperatures will kill the plant.'

Greenhouse potting shed bench with a watering can on display

(Image credit: Future PLC)

If you are worried about controlling your indoor or greenhouse temperatures, try wrapping your plant babies with a garden fleece like this one from Amazon, just as an extra precaution. 

'You could also invest in a greenhouse heater like this one from Amazon so you can create the optimal growing climate,' adds Chris, who urges you not to water your cannas 'until you see the first signs of growth in spring'.

And don't forget to regularly check the plants to ensure they are not rotting, too.

How to overwinter canna lilies as rhizomes

Alternatively, of course, you could try overwintering your canna lilies as rhizomes (basically the equivalent of a canna's root system).

In fact, this is the preferred method of Morris Hankinson, the director of Hopes Grove Nurseries.

Morris Hankinson of Hopes Grove Nurseries
Morris Hankinson

Morris Hankinson is the founder and managing director of Hopes Grove Nurseries Ltd, the UK’s only specialist grower-retailer of hedging plants, which he established after graduating with a Commercial Horticulture Degree from Writtle College, Essex in 1992.

To overwinter your cannas in this manner, you will need to get to work before the first frosts, and...

  1. Cut back the leaves of the canna lilies to about 4-6 inches above the soil level.
  2. Carefully dig up the canna lily bulbs from the pot. Be gentle to avoid damaging the bulbs.
  3. Shake off excess soil and let the bulbs dry for a few days in a cool, dry place.
  4. Once the bulbs are dry, store them in a cool, dark, and frost-free location for the winter. 
  5. You can store them in peat moss, sawdust, or sand to prevent drying out.
  6. Check on the bulbs occasionally during the winter to ensure they remain firm and healthy.
  7. In the spring, around the time of the last frost, replant the canna lily bulbs in fresh potting soil and keep up with watering and care.

FAQs

How do you store potted cannas over the winter?

There are several different options available to you when it comes to overwintering your potted canna lilies, but the easiest is to move your plants (in their containers) indoors or into a greenhouse, where the temperature will not drop below 12°C.

How do you overwinter canna lilies in the ground?

If you'd prefer to overwinter your cannas in the ground, Chris says that you should first 'inspect the bulbs for any signs of pests or diseases and using a clean pruning knife or deadheading snips, remove any damaged or diseased blooms or leaves to reduce the risk of them spreading to healthy parts of the plant'. 

Once this is done, you can prune and cut back the foliage to about 4-6 inches above soil level.

The Royal Horticultural Society (RHS) adds that cannas 'can be left outside all year in a sunny, sheltered position. However, apply a 15cm (6in) deep layer of mulch in winter and be prepared that there may be losses in very cold or wet winters.'

When should I cut my cannas down for the winter?

If you are planning to leave your cannas to their own devices, it might be best to wait until after the first frost, as this signals the plants to go dormant.

Ideally, then, you'll want to begin pruning in the late autumn or early winter, depending on when Jack Frost comes a-visiting. 

Whichever method you choose to go for, it's very simple to learn how to overwinter canna lilies.

And, with a little love and attention (and forward planning, of course), it's the best way to ensure another vibrant display come next summer. Is there any greater reward for a gardener than that?

Kayleigh Dray
Acting Content Editor

Kayleigh Dray became Ideal Home’s Acting Content Editor in the spring of 2023, and is very excited to get to work. She joins the team after a decade-long career working as a journalist and editor across a number of leading lifestyle brands, both in-house and as a freelancer.