Before planting it is a good idea to find your USDA Zone info to determine your garden 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 Grand Forks should be used to figure out when it's the best time to plant primroses.

Planting Calendar for Primroses

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

Primroses do ok in quite a bit of cold which means that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant primroses in Grand Forks is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant primroses and expect a good harvest is probably August. Any later than that and your primroses may not have a chance to fully mature. If you are starting your primroses indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Grand Forks the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Grand Forks and it can change quite a bit from year to year. Since half of the time in Grand Forks there is a last frost after May 15 be ready to protect your primroses if you have one of those late frosts.

USDA Zone Info for Grand Forks

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Grand Forks

You may be interested in your other planting guides for Grand Forks.