One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's possible to plant nierembergia in River Grove by referring to the USDA zone info.

Planting Calendar for Nierembergia

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

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

The earliest that you can plant nierembergia in River Grove 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 grow to maturity. You can get started a little bit earlier by starting your nierembergia indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in River Grove. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for River Grove may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in River Grove you get a frost after April 15 so be sure to be ready to cover your nierembergia if you have a surprise late frost.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.