The USDA Zone info is a great tool for gardeners to help us estimate 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.

The USDA zone info for Oak Ridge can be reffered to in order to figure out when it's the best time to plant nierembergia.

Planting Calendar for Nierembergia

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

Since nierembergia require warm weather you need to wait until after the last frost before you can plant them.

The earliest that you can plant nierembergia in Oak Ridge 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. If you wait 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

On average the last frost when the weather gets warmer is on April 15 in Oak Ridge. It might get as low as 0°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Oak Ridge and it will vary from year to year. Half of the time in Oak Ridge you get surprised by a frost after April 15 so make sure that you are prepared to protect your nierembergia in the event of a surprise late frost.

USDA Zone Info for Oak Ridge

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 Oak Ridge

You may be interested in your other planting guides for Oak Ridge.