The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when to plant purple coneflower in Great Falls by reviewing the USDA zone info.

Planting Calendar for Purple Coneflower

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

Since purple coneflower are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant purple coneflower in Great Falls 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 purple coneflower and expect a good harvest is probably August. Any later than that and your purple coneflower may not have a chance to grow to maturity. If you are starting your purple coneflower indoors then you might be able to get away with starting them a little bit 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.

Just be sure to remember that USDA zone info for Great Falls is just an average and the actual date of last frost changes from year to year. Since half of the time in Great Falls it frosts late in the year after May 15 be ready to protect your purple coneflower if you have a surprise late frost.

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.