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

You will be able to estimate when it's a good idea to plant cleome by using the USDA zone info for Missoula.

Planting Calendar for Cleome

Frost tolerance for cleome:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You really shouldn't plant cleome until after all chance of frost has passed because they require warm weather.

The earliest that you can plant cleome in Missoula 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 cleome and expect a good harvest is probably August. Any later than that and your cleome may not have a chance to fully mature. You can get started a few weeks earlier by starting your cleome indoors.

Last Frost Date

In Missoula the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Missoula is not always accurate the actual date of last frost will vary from year to year. Half of the time in Missoula there is a last frost after April 15 so always be ready to cover your cleome if you have a surprise late frost.

USDA Zone Info for Missoula

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Missoula

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