The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when to plant missouri primrose is to look at the USDA zone info for Ontario.

Planting Calendar for Missouri Primrose

Frost tolerance for missouri primrose:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant missouri primrose a bit earlier in the year because they do well in moderate cold.

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

The last month that you can plant missouri primrose and expect a good harvest is probably October. Any later than that and your missouri primrose may not have a chance to grow to maturity. You can get started a little bit earlier by starting your missouri primrose indoors.

Last Frost Date

The average date of last frost is January 31 in Ontario. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Ontario may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Ontario there is a last frost after January 31 be ready to protect your missouri primrose if you have a surprise 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.