One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Ottawa should be read to figure out when you can plant missouri primrose.

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 little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant missouri primrose in Ottawa 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 missouri primrose and expect a good harvest is probably September. You probably don't want to wait any later than that or else your missouri primrose may not have a chance to really do well. If you are starting your missouri primrose indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Ottawa the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for Ottawa is just an average and the actual date of last frost changes from year to year. Since half of the time in Ottawa there is a last frost after April 15 be ready to cover your missouri primrose if you have a surprise late frost.

USDA Zone Info for Ottawa

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 Ottawa

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