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 scarlet pimpernels in Havre should be determined by using the USDA zone info.

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.

Scarlet Pimpernels do ok in moderate cold which means that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant scarlet pimpernels in Havre 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. If you wait any later than that and your scarlet pimpernels may not have a chance to fully mature. If you are starting your scarlet pimpernels indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Havre. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Havre may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Havre there is a last frost after May 15 so just be sure to be ready to cover your scarlet pimpernels in the event of one of those late frosts.

USDA Zone Info for Havre

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 Havre

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