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

By looking at the USDA zone info for New Castle you will be able 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.

It's not a good idea to plant nierembergia until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant nierembergia in New Castle 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. You probably don't want to wait any later than that or else your nierembergia may not have a chance to fully mature. You can get started a few weeks earlier by starting your nierembergia indoors.

Last Frost Date

The average date of last frost is April 15 in New Castle. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for New Castle may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in New Castle there is a last frost after April 15 be ready to cover your nierembergia if you have a surprise late frost.

USDA Zone Info for New Castle

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in New Castle

You may be interested in your other planting guides for New Castle.