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 making a decision about when to plant watermelon is to refer to the USDA zone info for Altoona.

Planting Calendar for Watermelon

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

Watermelon do not do well in cold weather which tells us that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant watermelon in Altoona is May. However, you really should wait until June 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. Starting your watermelon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Altoona the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Altoona is just an average the actual date of last frost will vary from year to year. Half of the time in Altoona it frosts late in the year after May 15 so just be sure to be ready to protect your watermelon if you have a late frost.

USDA Zone Info for Altoona

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Altoona

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