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

The USDA zone info for Harrison can be reffered to in order to figure out when you can 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.

It's probably not a good idea to plant nierembergia until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant nierembergia in Harrison 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. 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

In Harrison the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Just be sure to remember that USDA zone info for Harrison may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Harrison it frosts late in the year after April 15 be ready to cover your nierembergia in the event of one of those late frosts.

USDA Zone Info for Harrison

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 Harrison

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