Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Great Falls you will be able to figure out when you can plant coreopsis.

Planting Calendar for Coreopsis

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

You can plant coreopsis a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant coreopsis 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 coreopsis and expect a good harvest is probably August. Any later than that and your coreopsis may not have a chance to fully mature. Starting your coreopsis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Great Falls. 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 is different every year. Half of the time in Great Falls there is a last frost after May 15 so make sure that you are ready to protect your coreopsis if you have 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.