One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. 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 figure out when it's possible to plant primula by checking out the USDA zone info for Grand Rapids.

Planting Calendar for Primula

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

You can plant primula a lot earlier in the year because they do well in cold.

The earliest that you can plant primula in Grand Rapids 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 really do well. If you are starting your primula indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Grand Rapids the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -35°F.

Since the USDA zone info for Grand Rapids is just an average the actual date of last frost will vary from year to year. Half of the time in Grand Rapids you get surprised by a frost after May 15 so make sure that you are prepared to cover your primula if you have a late frost.

USDA Zone Info for Grand Rapids

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Grand Rapids

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