The USDA Zone info is a great tool for gardeners to help us determine 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.

In Havre you can estimate when you can plant cerastium by using the USDA zone info.

Planting Calendar for Cerastium

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

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

The earliest that you can plant cerastium 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 cerastium and expect a good harvest is probably August. If you wait any later than that and your cerastium may not have a chance to grow to maturity. If you are starting your cerastium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Havre and it can change quite a bit from year to year. Since half of the time in Havre you get a frost after May 15 be ready to cover your cerastium 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.