I live with south exposure on Lake Ontario in Bath. I took my Canna Lily bulbs out last fall. When can I plant them in my outdoor planters.
Cannas are tropical plants which love full sun and warmth. You could start your cannas indoors in moist (but not wet) potting medium (soil). That way you’ll get a head start and they’ll bloom sooner so you can enjoy them longer. You could do that anytime now. Once planted, keep them in a warm dark location until they sprout, then move them to a bright sunny window. Don’t over water them or the rhizomes will rot.
You can plant (or transplant) them outdoors as soon as the threat of frost is gone. Rule of thumb is around the May long weekend. I have planted them outdoors sooner but there is a risk of losing the plants if there is a hard frost. Given that they will be planted in planters, the safest thing to do is start them indoors and transplant on the May long weekend.
A word of caution. Don’t plant more than one or two rhizomes in one planter as they will multiply and may prove difficult to remove in the fall.
For a useful website on growing cannas, click here.
Hope this helps.