In the fall, you can store calla and canna plants for next year. Both are easy to overwinter; here’s how:
Overwintering calla lilies
These wonderfully colourful plants are from South Africa. In their natural habitat, they grow and flower during the wet season, going dormant during the following dry season. Fortunately, these bulbs are super easy to store over the winter. They have a tough outer coat and equally tough interior, making them less likely to shrink during storage. Give them what they like and they’ll multiply like crazy.
If you’ve grown them in pots, cut off the foliage and bring them in before frost. Chances are they’re probably wet, and the tubers will be plump and full of moisture. If they’re dug out at this stage, they can be easily damaged, and the wound can cause your tuber to spoil during storage. Bulbs and tubers need to ripen in order to survive dormancy. They will slowly dry out, forming thicker, tougher coats that don’t mind handling. They like a cool, dark (but not freezing) spot.
If you really must unpot them, carefully remove the soil and re-package them in vermiculite or ever-so-slightly moist peat moss before storage. But why bother? This is a messy job and it’s easy to accidentally mix them up if you’re keeping track of different varieties. They’ll actually store far better left alone in their pots. It’s what I’ve done successfully for years.
If you’re wondering where to put all your pots, fear not. You can stack them once they’ve dried out. The only thing to watch for are early sprouts growing as your callas wake up. (They don’t grow too well under another pot!) This shouldn’t happen until late winter, but sometimes they surprise you. Keeping them cool helps prevent them from sprouting too early.
Overwintering canna lilies
These popular plants have adorned Canadian gardens for generations. Their lush, tropical foliage and non-stop flowering are one of the highlights of summer containers and gardens. They’re native to tropical Asia where they flourish in the hot, wet growing season; some species reach seven feet (2 m). Here in Canada, where our winters are hardly hot and tropical, our shorter days and cooler weather signal that it’s time to move them indoors. They hate cold weather, so bring them in when overnight temperatures get into the low, single digits.
Canna virus – a bad news, good news story
The bad news: Unfortunately, there is a nasty virus in virtually all the big cannas grown in France, Israel, the Netherlands, Australia and the U.S., which are where almost all the canna sold in Canada come from. The disease was first identified years ago but little has been done to stop its spread. It has spread throughout the large nurseries of the world, with only a handful offering virus-free, healthy stock.
It’s known as yellow streak virus, and the name says it all. It first appears as faint yellow streaks in the foliage, increasingly spreading, eventually leading to distorted foliage and death. Like many plant viruses, it’s spread by sucking insects like aphids. There is no cure. Dispose of infected plants and surrounding soil in the garbage, not in your compost. The tragedy is you can’t see any evidence on the root or even early-season foliage. But the mature foliage in fall will show if the plant is infected, which leads me to…
The good news: Fortunately, the majority of cannas we grow aren’t bought. They’re traded, passed on, shared with family and neighbours or traded at horticultural societies. These have likely been around long before the virus even existed. If they’re healthy they’re probably fine. In fact, several canna nurseries and collections were saved by collecting healthy rhizomes from isolated virus-free gardens. So check your canna foliage carefully. If in doubt, throw them out.
Chop the foliage off a few inches above soil level. Cannas in containers can be brought indoors. If they’re in big pots, you’re better off lifting them as you would those growing in the garden. This requires some care because a healthy canna rhizome (root) will have grown a lot bigger over the summer.
Allow their plump, water-filled roots to ripen a bit before storage. Once ripened, you can remove any soil and place them in clear plastic bags filled with very lightly moistened (not damp) peat moss, storing the sealed bags in a cool, dark place. Check them from time to time to make sure they haven’t rotted (you’ll see a mushy area). Just cut this off, let the root dry off and re-store again in peat moss.
mary bandar says
which month i should replant the calla lily
I live in North Carolina with HOT summers. I have Calla Lillies in an outdoor bed that I need to redo. Thought they were dead after a mild winter. In early summer they popped back out. Now I need to move them and store for replanting in another area in the spring. How should I do this?
My wintered canna lilies have tall leggy sprouts on them and they can’t go outside yet. Should I cut them off?
Romana Meza says
M y Canna Lily is in a very large pot an I can’t bring it in for winter . After cutting it back, is it possible to just cover with some protective garden cloth?
Waltrud Mueller says
Can you leave Dahlia bulbs/corms in pots as well as calla
I have callas in a pot, because I didn’t know any better I’ve never given them any special treatment. Even with frost I’ve never taken them inside. Nevertheless they have always thrived, look very healthy and will bloom every year. Reading all the above I guess I’ve been lucky. Since it seems happy where it is and with my non treatment I don’t dare to change it. The only extra they’ll get is a little driedncow dung powder every spring.
Cheryl Sullivan says
Do you water cannas that you bring in if you grow them in pots
Merla Taylor says
Same question as Ms. Sullivan above.
Do you water cannas that you bring in if you have grown them in pots
My calla lilly seems to be really leggy, it won’t stay standing on its own. It’s in a pot and indoors. Someone said to put it in a deeper pot? After reading comments I don’t think that’s the answer. It’s late September here, should I cut it back?
Leggy, indoor plants usually become that way because they don’t have enough sunlight. Cannas are meant to be outdoor plants, Even an indoor, sunny window seldom has more sunlight than an outdoor semi-shady to shay spot outdoor.
My calla lily lives in my pond in the summer and blooms frequently when inside in the winter (in Calgary).
This year, it came in and about a month later I discovered black bugs crawling on it. The greenhouse thinks Black Aphids I can’t find any information about treating them. These tiny bugs ARE black and the crawl and fly.
I had the same nasty problem. I kept washing the stems with a cloth and soapy water and it reduced them. This year I m trying neem oil mixed with water and soap and spraying the soil. Fingers crossed.
josie thurgood says
when do i start watering my overwintered pot planted lily bulbs please.
Dugald Cameron says
Calla Lilies are native to the Tugella river area of South Africa, where they begin growing after the dry season. Needless to say, it’s a warm country which is important to remember with Calla. Anxious as we all are to “get things growing”, don’t rush them outside until nights are above freezing. They’re not keen on cold.
You can start watering 1 month before it’s warm enough to move them outdoors.
Terry Menge says
I have many Canna bulbs that I dug from my yard last fall and have placed them in peat moss in a dark place in the basement. I lightly water them every 6 weeks or so. I live in Minnesota so it is generally the middle to late May before I can safely plant outdoors. How long does a Canna bulb need to be dormant and if I wanted to start the plants early in my house when would be a good time to start them growing again?
Dugald Cameron says
Cannas thrive on heat. Their dormancy isn’t so much required, but in cold season gardens like yours and mine, a function of the lower light levels and temperatures of fall and winter. Your storage sounds ideal and getting a head start in our short season is a good idea.
Pot them up 4 weeks before your planting out date, giving them warmth and light. Don’t be in a hurry to move them outside until night temperatures are over 60 and plant in a fertile rich soil with plenty of moisture. I find they grow best in large, black or dark coloured containers which get much warmer faster than the ground.
carol anderson says
I am in Calgary I have never had canna lilies but did this year I took them out of pot’s and washed them put them on news paper in my storage are dark and dry . yesterday I took the wet newpaper of them and put dry and put them in 3 container’s but did not cover them with newspaper. I think I may have washed them to good did I do wrong
Dugald Cameron says
Planting depth is critical to flowering calla.They like a shallow planting with approx 1/2 to 1 inch (1 to 2.5 cm) of soil over the top of their bulbs (corms). Planted deeper, they’ll grow lots of foliage but few, if any, flowers. The good news is that their corms will likely have grown much larger. They may be big enough to divide when you replant so you’ll have more callas to enjoy/share next summer.
Like other summer-flowering bulbs, they like to be fed, too. Any balanced fertilizer (such as 20-20-20) will do, but one with a lower first number is ideal.
The rule of thumb with potted bulbs is that you’ll know they’re happy if their bulbs are bigger at the end of then season than when you potted them.
Marian Soper-Severinac says
Thank you for the information on storing Canna and Calla Lillies. I grow both and love them! Unfortunately, my Callas didn’t do well this year and not sure why. I planted them early indoors in pots, then when danger of frost was over, moved them to a sunny location on our deck. Out of all the bulbs planted, probably 10 or more, only got two blooms over the summer. What might I have done wrong? I dry the bulbs and pack them in sand for the winter and store in a cool location. Other years, I have had continual blooms all summer.
Dugald Cameron says
There could be a number of reasons, but my I need a little more information first. Did they grow well in spite of few flowers? Did you give them any fertilizer?