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

You should be able to estimate when to plant primroses by referring to the USDA zone info for Medical Lake.

Planting Calendar for Primroses

Frost tolerance for primroses:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant primroses much earlier in the year because they are very cold tolerant.

The earliest that you can plant primroses in Medical Lake 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 primroses and expect a good harvest is probably September. Any later than that and your primroses may not have a chance to grow to maturity. If you are starting your primroses 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 Medical Lake. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for Medical Lake is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Medical Lake you get surprised by a frost after April 15 so make sure that you are prepared to cover your primroses if you have a late frost.

USDA Zone Info for Medical Lake

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Medical Lake

You may be interested in your other planting guides for Medical Lake.