Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant nierembergia by using the USDA zone info for Herndon.

Planting Calendar for Nierembergia

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

You really shouldn't plant nierembergia until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant nierembergia 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 nierembergia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your nierembergia may not have a chance to fully mature. Starting your nierembergia indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Herndon. In the coldest months of winter you can expect an average low temperature of 0°F.

Just be sure to remember that USDA zone info for Herndon may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Herndon you get surprised by a frost after April 15 be ready to protect your nierembergia if you have a surprise late frost.

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.