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 USDA zone info for Washington can be reviewed to determine when to 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.

Missouri Primrose do well in moderate cold which means that you can plant them earlier than other frost tender plants.

The earliest that you can plant missouri primrose in Washington 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. You can get started a little bit earlier by starting your missouri primrose indoors.

Last Frost Date

On average the last frost is on April 15 in Washington. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Washington may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Washington it frosts late in the year after April 15 be ready to protect your missouri primrose if you have a late frost.

USDA Zone Info for Washington

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 Washington

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