The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant coreopsis in Havre can be determined by reviewing the USDA zone info.

Planting Calendar for Coreopsis

Frost tolerance for coreopsis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant coreopsis a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant coreopsis in Havre 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 coreopsis and expect a good harvest is probably August. If you wait any later than that and your coreopsis may not have a chance to really do well. You can get started a little bit earlier by starting your coreopsis indoors.

Last Frost Date

The average date of last frost is May 15 in Havre. In the coldest months of winter you should expect an average low temperature of -30°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Havre and it will vary from year to year. Half of the time in Havre you get surprised by a frost after May 15 so make sure that you are prepared to protect your coreopsis if you have a surprise late frost.

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.