The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Zone 4a you will be able to determine when it's a good idea to plant scarlet pimpernels.

Planting Calendar for Scarlet Pimpernels

Frost tolerance for scarlet pimpernels:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant scarlet pimpernels just a tiny bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant scarlet pimpernels in Zone 4a is April. However, you really should wait until May if you don't want to take any chances.

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

Last Frost Date

In Zone 4a the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 4a and it is different every year. Since half of the time in Zone 4a you get surprised by a frost after May 15 be ready to protect your scarlet pimpernels if you have a late frost.

USDA Zone Info for Zone 4a

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 Zone 4a

You may be interested in your other planting guides for Zone 4a.