Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's the best time to plant primroses by looking at the USDA zone info for Isanti.

Planting Calendar for Primroses

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

Since primroses are very cold tolerant you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant primroses in Isanti 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. Starting your primroses indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Isanti. In the coldest months of winter you can expect an average low temperature of -30°F.

Since the USDA zone info for Isanti is an average the actual date of last frost is different every year. Since half of the time in Isanti it frosts late in the year after May 15 be ready to cover your primroses if you have one of those late frosts.

USDA Zone Info for Isanti

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 Isanti

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