The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's a good idea to plant calla lily in Ontario by reviewing the USDA zone info.

Planting Calendar for Calla Lily

Frost tolerance for calla lily:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's not a good idea to plant calla lily until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant calla lily in Ontario is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant calla lily and expect a good harvest is probably September. Any later than that and your calla lily may not have a chance to really do well. If you are starting your calla lily indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Ontario the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Ontario and it changes from year to year. Since half of the time in Ontario you get a frost after January 31 be ready to protect your calla lily if you have one of those late frosts.

USDA Zone Info for Ontario

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Ontario

You may be interested in your other planting guides for Ontario.