When to Plant Watermelon in Mattoon, IL

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of figuring out when you can plant watermelon is to use the USDA zone info for Mattoon.


Planting Calendar for Watermelon

Frost tolerance for watermelon: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

Since watermelon do not do well in cold weather you really should wait until after the last frost has passed before you can plant them.

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

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

Last Frost Date

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

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Mattoon and it will vary from year to year. Half of the time in Mattoon you get a frost after April 15 so make sure that you are ready to protect your watermelon in the event of a surprise late frost.

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.