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.

The first chance to plant missouri primrose in River Rouge should be estimated by reviewing the USDA zone info.

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 just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant missouri primrose in River Rouge 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 little bit earlier.

Last Frost Date

The average date of last frost is April 15 in River Rouge. In the coldest months of winter you should expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for River Rouge is just an average and the actual date of last frost changes from year to year. Since half of the time in River Rouge 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 River Rouge

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in River Rouge

You may be interested in your other planting guides for River Rouge.