One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when it's the best time to plant chrysanthemums is to check out the USDA zone info for Great Falls.

Planting Calendar for Chrysanthemums

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

Chrysanthemums can survive in mild cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

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

Last Frost Date

In Great Falls the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Great Falls may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Great Falls you get a frost after May 15 be ready to protect your chrysanthemums 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.