One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

In Walla Walla you can determine when to plant missouri primrose 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.

Missouri Primrose are one of those plants that can tolerate a little bit of cold weather which means that you can get them planted earlier than more sensitive plants.

The earliest that you can plant missouri primrose in Walla Walla 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. If you wait any later than that and your missouri primrose may not have a chance to really do well. You can get started a couple of weeks earlier by starting your missouri primrose indoors.

Last Frost Date

The average date of last frost is April 15 in Walla Walla. You should expect an average low temperature of 0°F in the coldest months of winter.

Keep in mind that USDA zone info for Walla Walla is just an average and the actual date of last frost will vary from year to year. Half of the time in Walla Walla you get surprised by a frost after April 15 so always be ready to protect your missouri primrose if you have one of those late frosts.

USDA Zone Info for Walla Walla

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Walla Walla

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