The USDA Zone info is a great tool for gardeners to help us figure out your gardening 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 estimating when it's the best time to plant string beans is to consult the USDA zone info for Herndon.

Planting Calendar for String beans

Frost tolerance for string beans:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since string beans require warm weather it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant string beans in Herndon 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 string beans and expect a good harvest is probably August. Any later than that and your string beans may not have a chance to fully mature. If you are starting your string beans indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Herndon the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Herndon is just an average the actual date of last frost changes from year to year. Half of the time in Herndon you get surprised by a frost after April 15 so make sure that you are prepared to cover your string beans if you have one of those late frosts.

USDA Zone Info for Herndon

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Herndon

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