One of the best tools that you have as gardeners to help us determine 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.

The USDA zone info for Great Falls should be read to figure out when it's a good idea to plant aubretia.

Planting Calendar for Aubretia

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

Since aubretia are very cold tolerant you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant aubretia 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 aubretia and expect a good harvest is probably August. If you wait any later than that and your aubretia may not have a chance to fully mature. If you are starting your aubretia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Great Falls the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -30°F.

It's important to remember that USDA zone info for Great Falls is an average and the actual date of last frost changes from year to year. Half of the time in Great Falls there is a last frost after May 15 so make sure that you are ready to cover your aubretia 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.