One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of estimating when it's the best time to plant watermelon is to consult the USDA zone info for Portsmouth.

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 are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant watermelon in Portsmouth 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. Starting your watermelon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Portsmouth. You should expect an average low temperature of 10°F in the coldest months of winter.

It's important to remember that USDA zone info for Portsmouth is an average and the actual date of last frost will vary from year to year. Since half of the time in Portsmouth it frosts late in the year after March 15 be ready to cover your watermelon if you have a late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Portsmouth

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