When to Plant Cosmos in Harrisonville, MO

One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's possible to plant cosmos by looking at the USDA zone info for Harrisonville.


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.

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant cosmos
Possibly ok, but a risky time to plant cosmos
Probably not a good time to plant cosmos

The earliest that you can plant cosmos in Harrisonville 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 cosmos and expect a good harvest is probably August. Any later than that and 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

In Harrisonville the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Harrisonville is just an average and the actual date of last frost changes from year to year. Half of the time in Harrisonville last frost occurs after April 15 so just be sure to be ready to cover your cosmos in the event of one of those late frosts.

USDA Zone Info for Harrisonville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Harrisonville

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