The USDA Zone info is a great tool for gardeners to help us estimate 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.

The first opportunity to plant mustard in Ontario can be figured out by reviewing the USDA zone info.

Planting Calendar for Mustard

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

You can not plant mustard until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant mustard in Ontario is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant mustard and expect a good harvest is probably August. If you wait any later than that and your mustard may not have a chance to fully mature. Starting your mustard indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ontario. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Ontario is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Ontario last frost occurs after April 15 so make sure that you are ready to protect your mustard if you have one of those late frosts.

USDA Zone Info for Ontario

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ontario

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