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.

A common way of making a decision about when it's the best time to plant primroses is to refer to the USDA zone info for Ishpeming.

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 one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant primroses in Ishpeming 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. You probably don't want to wait any later than that or else your primroses may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your primroses indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Ishpeming. It might get as low as -25°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Ishpeming may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Ishpeming it frosts late in the year after May 15 be ready to cover your primroses in the event of one of those late frosts.

USDA Zone Info for Ishpeming

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Ishpeming

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