One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Richmond you can estimate when to plant nierembergia by looking at the USDA zone info.

Planting Calendar for Nierembergia

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

Since nierembergia are not cold tolerant it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant nierembergia in Richmond 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. You can get started a couple of weeks earlier by starting your nierembergia indoors.

Last Frost Date

The average date of last frost is April 15 in Richmond. In the coldest months of winter you can expect an average low temperature of -5°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Richmond and it can change quite a bit from year to year. Since half of the time in Richmond last frost occurs after April 15 be ready to cover your nierembergia in the event of a surprise late frost.

USDA Zone Info for Richmond

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Richmond

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