Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant rosemary in Havre can be figured out by referring to the USDA zone info.

Planting Calendar for Rosemary

Frost tolerance for rosemary:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Rosemary tend to make it in pretty solid cold which tells us that you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

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

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.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Havre and it is different every year. Half of the time in Havre you get surprised by a frost after May 15 so just be sure to be ready to protect your rosemary if you have 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.