I'd get them started in small pots indoors today! I started mine two to three weeks ago, and I was running late. Only a couple of them have sprouted yet.

Plant dahlias with the neck above the soil, but otherwise plant indoors in small pots. Transplant everything to bigger pots when you move them out.

BP

Laura, you don't mention where in Ontario you are, so it is really hard to give advice.

It is too soon to plant outside now, where I live in southern Ontario. This week, we are expecting frost in the evenings, although the days are going to be lovely.

As Bonnie mentions, start your canna, calla, and dahlia now inside. These can be taken outside during the day, but should be brought back in for the evenings that are cold. I won't be planting in the ground here in Rockwood, until after the full moon at the end of May. I'll be watching the forecast carefully then.

Have fun, and enjoy your garden.