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

A common way of determining when it's possible to plant missouri primrose is to use the USDA zone info for Silvis.

Planting Calendar for Missouri Primrose

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

Since missouri primrose are moderately cold tolerant you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant missouri primrose in Silvis 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. Any later than that and your missouri primrose may not have a chance to grow to maturity. If you are starting your missouri primrose indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Silvis is just an average and the actual date of last frost is different every year. Since half of the time in Silvis there is a last frost after April 15 be ready to cover your missouri primrose if you have a late frost.

USDA Zone Info for Silvis

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 Silvis

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