Before planting it is a good idea to find your USDA Zone info to figure out 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.

The first opportunity to plant nierembergia in Gretna should be figured out by checking out the USDA zone info.

Planting Calendar for Nierembergia

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

It's probably not a good idea to plant nierembergia until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant nierembergia in Gretna is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant nierembergia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your nierembergia may not have a chance to really do well. If you are starting your nierembergia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Gretna. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Gretna is just an average the actual date of last frost is different every year. Half of the time in Gretna it frosts late in the year after February 15 so be sure to be ready to cover your nierembergia in the event of a surprise late frost.

USDA Zone Info for Gretna

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Gretna

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