One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Ontario you should be able to figure out when you can plant cilantro.

Planting Calendar for Cilantro

Frost tolerance for cilantro:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant cilantro a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant cilantro 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 cilantro and expect a good harvest is probably September. You probably don't want to wait any later than that or else your cilantro may not have a chance to grow to maturity. If you are starting your cilantro indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Ontario. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for Ontario is an average the actual date of last frost changes from year to year. Since half of the time in Ontario there is a last frost after January 31 be ready to cover your cilantro 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.