Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Ontario you should be able to estimate when it's the best time to plant bishop's weed.

Planting Calendar for Bishop's Weed

Frost tolerance for bishop's weed:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since bishop's weed do well in cold you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant bishop's weed 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 bishop's weed and expect a good harvest is probably September. If you wait any later than that and your bishop's weed may not have a chance to grow to maturity. Starting your bishop's weed indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Ontario. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Ontario is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Ontario there is a last frost after April 15 so just be sure to be ready to protect your bishop's weed 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.