One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Ontario you can figure out when it's possible to plant mustard by referring to the USDA zone info.

Planting Calendar for Mustard

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

Since mustard do not do well in cold weather it is necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant mustard 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 mustard and expect a good harvest is probably September. Any later than that and your mustard may not have a chance to grow to maturity. Starting your mustard indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Ontario. You can expect an average low temperature of 30°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Ontario and it is different every year. Since half of the time in Ontario it frosts late in the year after January 31 be ready to cover your mustard in the event of a late frost.

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.