One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's the best time to plant primula is to look at the USDA zone info for Coldwater.

Planting Calendar for Primula

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

Since primula 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 plants that might not handle the cold.

The earliest that you can plant primula in Coldwater is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant primula and expect a good harvest is probably September. You probably don't want to wait any later than that or else your primula may not have a chance to really do well. You can get started a little bit earlier by starting your primula indoors.

Last Frost Date

In Coldwater the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Coldwater is an average and the actual date of last frost is different every year. Half of the time in Coldwater there is a last frost after April 15 so make sure that you are prepared to protect your primula if you have a surprise late frost.

USDA Zone Info for Coldwater

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Coldwater

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