One of the first steps you take when you are determining 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.

By looking at the USDA zone info for Havre you should be able to estimate when it's possible to plant chervil.

Planting Calendar for Chervil

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

Chervil are barely cold tolerant which tells us that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant chervil 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 chervil and expect a good harvest is probably August. You probably don't want to wait any later than that or else your chervil may not have a chance to grow to maturity. Starting your chervil indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Havre. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Havre is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Havre you get a frost after May 15 so just be sure to be ready to cover your chervil in the event of a 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.