Since I live and garden in a warmer climate (at least I think so), I really don't know if I can give you good advice, Morgan. Do you get hard frosts and/or does your ground freeze?

If just frost then the frost will kill the top growth down. Just cut those down and leave the rhizomes in the ground. You might want to mulch with shredded leaves and come next spring, when the temps start to warm and the days get longer, pull the mulch back and let the soil dry out. For your potted cannas I would move them to a protected area, like under an awning or trees, or even in a garage.

If your ground freezes, I think it might be best if you dig them up, cut away the dead or dying foliage and stalks, dry them for a few days, and store them in a dry area. To get them to an early start plant them into containers in the late winter/early spring and give them as much warmth you can.

I do know of a few people who live in an area where the ground freezes and have successfully overwintered their rhizomes in the ground. However, they put tons of mulch over the cannas to keep the ground from freezing. They've lost some and had others come back. I really think it all depends on the hardiness of the canna/cannas that you have. Some can take alot of abuse and severe temps while others can't. As long as the roots/rhizomes survive the cold months then you'll have cannas again next year.

Hope this has helped some.

Jenna

Hi Morgan. Whereabouts in the UK are you? I'm in London, which in terms of coldest temperature is roughly equivalent to US zone 8b/9. However one big difference is that our winters (with the exception of the odd dry year, such as last year) can have a lot of rain, and I think it's these cold, wet conditions that can lead to rotting or dormant rhizomes, especially if you have heavy soil.

Jenna's advice is pretty comprehensive, but below is my experience of growing them.

Last year I dug up all my Canna after a frost had wilted the foliage (I think it was late Oct/early Nov). I washed off the soil, let them dry, dusted the rhizomes with sulphur powder (to help prevent fungal disease), packed them all in dryish compost and left them somewhere dark, cold but frost-free. Around April I potted them all up and put them in the greenhouse to get them started into growth.

However, this year I plan only to dig up my really special Cannas, and I'll leave the rest in the ground (as with Dahlias), just with a good covering of mulch. But as Jenna says, the ones in the ground will be slower to get going than the ones started in warmth.

I live in the central part of England and we are subject to spells of hard frosts during the Winter months.
Therefore I will take your advice and lift them from the ground, dry them off and store away, thank you for your very sound advice.
I have a lot to learn re cannas.

Oops... I meant "cold, wet conditions lead to rotting OF dormant rhizomes" not "OR dormant rhizomes".

Good luck with your overwintering!

I have now lifted my canna's, left them to dry off, dusted with yellow sulphur,placed them in to med pot's and packed bark chipping around them.
Placed them in a frost free shed.
Thank for all your advise.

I bet you're glad you've got that out of the way! I have that task to deal with this coming weekend.

Have you got the task of lifting your canna's out of the way? How often do you check your canna's over during the Winter months and do they need some water?

should i start my canna bulbs inside in my basement green house!

Assuming you have the necessary growing conditions, you would certainly get a great early season start and receive much earlier blooms for your cannas.
Regards,
Kent