One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Havre should be reffered to in order to determine when you can plant salvia.

Planting Calendar for Salvia

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

Since salvia are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant salvia 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 salvia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your salvia may not have a chance to grow to maturity. If you are starting your salvia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Havre is just an average 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 always be ready to protect your salvia in the event of 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.