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.

The USDA zone info for Mattoon can be read to estimate when it's the best time to plant coreopsis.

Planting Calendar for Coreopsis

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

Coreopsis tend to make it in some cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant coreopsis in Mattoon is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant coreopsis and expect a good harvest is probably September. 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 little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Mattoon. You can expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Mattoon is just an average and the actual date of last frost is different every year. Half of the time in Mattoon you get surprised by a frost after April 15 so make sure that you are ready to cover your coreopsis if you have one of those late frosts.

USDA Zone Info for Mattoon

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 Mattoon

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