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

By looking at the USDA zone info for Great Falls you should be able to figure out when it's possible to plant borage.

Planting Calendar for Borage

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

Borage do well in moderate cold which means that you can plant them earlier than more sensitive plants.

The earliest that you can plant borage in Great Falls 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 borage and expect a good harvest is probably August. You probably don't want to wait any later than that or else your borage may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your borage indoors.

Last Frost Date

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

Since the USDA zone info for Great Falls is just an average the actual date of last frost will vary from year to year. Half of the time in Great Falls there is a last frost after May 15 so just be sure to be ready to protect your borage in the event of one of those late frosts.

USDA Zone Info for Great Falls

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 Great Falls

You may be interested in your other planting guides for Great Falls.