Hi Everyone I have had some difficultly in growing Canna Lillies. We live in Tsawwassen and quite a few homes have good size beds of these beautiful plants. I would rather not plant them in containers but put them in a raised bed with our banana tree and Caladium species to give a more tropical look. I believe some of these people are leaving the rhizomes in the ground over the winter. Has anyone done this? or can anyone suggest an easy way to store these plants and give them a head start before spring planting. I have limited space and no green house. Thanks for any info. bcguys
At the building where I teach we have an enclosed (on three sides) courtyard that opens south. Right beside a light-coloured wall at the north-end of that courtyard, facing sourth, and surrounded by concrete on all sides (i.e. sidewalks on three sides, wall on fourth) there is a Canna lilly (I believe they are 'Madam Butterfly') bed. As far as I know, no one takes them out of the ground over winter. We are Zone 6b, these cultivars are hardy to 7b. You are in Tsawwassen, so I would think that you would be OK as you should be Zone 8. In the five years I lived in Vancouver, I only remember the temperature getting below zero C only once. The key to doing this is to create a microclimate that is warmer than your zone, which is what I'm thinking has happened here.
I'm on Salt Spring, same zone as you, I don't take any of my cannas out, I do mulch them, but not for fear of losing them, I mulch everything in the garden. I haven't lost one yet.
I used to leave canna tubers in the ground, having lifted enough rhizomes to pot up and keep in my garage for the next season's growth. The surplus are left in the ground. In the first 3 years (98-2001), the rhizomes survived winter just once, with mulching. I am up on a hill in Coquitlam, so gets sub-zero cold periods every winter, with temperatures occassionally to minus double digit Celcius. I believe that it only need a single episode of freezing to kill the plant. Although, you are probably quite safe where you are to leave the tubers in the ground, it is possible that a single night of really cold subzero temperature will kill it. So, do mulch. And better still, for insurance, lift a few healthy rhizomes, pot them up in Sunshine #4, keep the media moist but not soaking wet, and leave in a frost free area - in your garage, for example - over the winter.
The risk of leaving cannas in the ground is more from winter wet than freezing- the bulbs rot. A couple of things that can help overwintering are making sure they are in a well drained spot that won't become soggy with the winter rains, and, instead of cutting the tops off once they have been frost killed, bend them over. The practice of cutting them back createds an opening for rain to get to the top of the rhizome and rot it. Bending the stem provides some protection. If your cannas are planted in a site you suspect is too wet in winter, try putting a piece of bubble wrap over the soil after cutting/ bending the foliage back, then covering it with mulch/wood chips (to keep in from blowing away). We do this for both cannas and bananas that are in marginal soil. Most years it works.
I've never taken my cannas inside, and they've always come up for the three years that I've grown them. I haven't mulched them either. I live in zone 7 or 8. They are by a south wall in front of an unheated shop.
I live in Michigan. For an experiment I am leaving some in over winter. They are on the side of my house, and I planted them deeper then I usually do. Any suggestions?
I live in Iowa,zone 5.Last fall I when I dug my cannas,I didn't get them all out of the ground.This spring one did come up from that root.No mulch.It did not bloom though.Don't think I would make a habit out of leaving them out all winter though.
silver creek writes, "The risk of leaving cannas in the ground is more from winter wet than freezing- the bulbs rot. A couple of things that can help overwintering are making sure they are in a well drained spot that won't become soggy with the winter rains, and, instead of cutting the tops off once they have been frost killed, bend them over. The practice of cutting them back createds an opening for rain to get to the top of the rhizome and rot it. Bending the stem provides some protection. If your cannas are planted in a site you suspect is too wet in winter, try putting a piece of bubble wrap over the soil after cutting/ bending the foliage back, then covering it with mulch/wood chips (to keep in from blowing away). We do this for both cannas and bananas that are in marginal soil. Most years it works." This is the best advice anyone can get for growers in the PNW, Bar none. The stem can act as a wick if it's cut down, allowing rain water into the rhizome, rotting it. Thanks silver creek and cheers, LPN.
Thanks for the tip LPN. I have some bubble wrap saved and now I know what I'll be doing with it. My Cannas haven't had any frost yet, but I'll bend them over instead of cutting them off when it happens.
