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

The first chance to plant cosmos in Glendive should be figured out by referring to the USDA zone info.

Planting Calendar for Cosmos

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

Since cosmos 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 other plants that might not handle the cold.

The earliest that you can plant cosmos in Glendive 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 cosmos and expect a good harvest is probably August. You probably don't want to wait any later than that or else your cosmos may not have a chance to fully mature. Starting your cosmos indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Glendive. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Glendive is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Glendive there is a last frost after May 15 be ready to protect your cosmos in the event of a late frost.

USDA Zone Info for Glendive

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 Glendive

You may be interested in your other planting guides for Glendive.