The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant nierembergia in Columbia should be determined by reviewing 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.

Since nierembergia do not do well in cold weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant nierembergia in Columbia 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 really do well. Starting your nierembergia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Columbia. In the coldest months of winter you should expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Columbia is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Columbia you get a frost after April 15 be ready to protect your nierembergia if you have a surprise late frost.

USDA Zone Info for Columbia

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Columbia

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