One of the best tools that you have as gardeners to help us estimate 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.

The first chance to plant nierembergia in Manassas should be determined by looking at the USDA zone info.

Planting Calendar for Nierembergia

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

Nierembergia do not do well in cold weather which means that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant nierembergia in Manassas 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. Any later than that and your nierembergia may not have a chance to fully mature. If you are starting your nierembergia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Manassas. You should expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Manassas is just an average and the actual date of last frost is different every year. Since half of the time in Manassas you get a frost after April 15 be ready to cover your nierembergia in the event of one of those late frosts.

USDA Zone Info for Manassas

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 Manassas

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