One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

In Havre you can figure out when it's possible to plant santolina by checking out the USDA zone info.

Planting Calendar for Santolina

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

Santolina can survive in pretty solid cold which tells us that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant santolina 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 santolina and expect a good harvest is probably August. Any later than that and your santolina may not have a chance to really do well. You can get started a couple of weeks earlier by starting your santolina indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Havre. In the coldest months of winter you can expect an average low temperature of -30°F.

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 there is a last frost after May 15 so make sure that you are ready to protect your santolina 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.