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.

The USDA zone info for Rock Island can be reviewed to figure out when it's a good idea to plant watermelon.

Planting Calendar for Watermelon

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

It's probably not a good idea to plant watermelon until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant watermelon in Rock Island 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. You probably don't want to wait any later than that or else your watermelon may not have a chance to really do well. You can get started a few weeks earlier by starting your watermelon indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Rock Island. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Rock Island is just an average the actual date of last frost is different every year. Since half of the time in Rock Island you get a frost after April 15 be ready to protect your watermelon if you have one of those late frosts.

USDA Zone Info for Rock Island

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 Rock Island

You may be interested in your other planting guides for Rock Island.