One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant primula in Ishpeming should be estimated by using the USDA zone info.

Planting Calendar for Primula

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

Primula are one of those plants that can tolerate quite a bit of cold weather which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant primula 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 primula and expect a good harvest is probably August. You probably don't want to wait any later than that or else your primula may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your primula indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Ishpeming. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Ishpeming is just an average the actual date of last frost will vary from year to year. Half of the time in Ishpeming there is a last frost after May 15 so just be sure to be ready to protect your primula in the event of a surprise late frost.

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.