One of the first steps you take when you are estimating your gardening schedule is find your 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.

One way of figuring out when it's possible to plant watermelon is to look at the USDA zone info for Willowbrook.

Planting Calendar for Watermelon

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

Since watermelon are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant watermelon in Willowbrook 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 fully mature. You can get started a little bit earlier by starting your watermelon indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Willowbrook and it changes from year to year. Half of the time in Willowbrook there is a last frost after April 15 so just be sure to be ready to protect your watermelon in the event of a late frost.

USDA Zone Info for Willowbrook

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 Willowbrook

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