Although I usually wait until May, I’m wondering if I can plant my canna, calla and dahlia bulbs now, since the weather is so warm.
We’re all eager to get into our gardens and get a head start after such a long cold winter. But the temperature is still dropping to 4 or 5 C many nights and cannas, callas and dahlias all need warm soil to thrive.
Cannas and callas are tropical plants that grow from rhizomes, thick stems with roots and shoots coming out from them. Dahlias are also from a warm climate (they are native to Mexico) and grow from tubers. All of them will struggle in cold soil, so you shouldn’t be in a hurry to put them in. In Toronto, you should wait until at least May 9th, which is the last frost date cited by Environment Canada (based on a 30-year average between 1960 and 1990).
It’s recommended that you put them in around the time you would plant tomatoes — so perhaps even a little later than May 9th — depending on whether the nights as well as the days are consistently warm.