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 should be able to estimate when to plant nierembergia by checking out the USDA zone info for Oak Park.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably a bad idea to plant nierembergia until after the last frost has passed because they require warm weather.

The earliest that you can plant nierembergia in Oak Park 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 couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Oak Park. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Oak Park may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Oak Park you get a frost after April 15 be ready to cover your nierembergia if you have one of those late frosts.

USDA Zone Info for Oak Park

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 Oak Park

You may be interested in your other planting guides for Oak Park.