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

In Coal City you can figure out when it's a good idea to plant nierembergia by looking at the USDA zone info.

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 a bad idea to plant nierembergia until after the last frost because they are not cold tolerant.

The earliest that you can plant nierembergia in Coal City 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. Starting your nierembergia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Coal City. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Coal City is an average the actual date of last frost is different every year. Since half of the time in Coal City you get surprised by a frost after April 15 be ready to protect your nierembergia if you have a surprise late frost.

USDA Zone Info for Coal City

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 Coal City

You may be interested in your other planting guides for Coal City.