One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Willowbrook you can determine when it's a good idea to plant impatiens by checking out the USDA zone info.

Planting Calendar for Impatiens

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

You can not plant impatiens until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant impatiens in Willowbrook 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 impatiens and expect a good harvest is probably August. Any later than that and your impatiens may not have a chance to fully mature. Starting your impatiens indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Willowbrook. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Willowbrook is not always accurate the actual date of last frost changes from year to year. Half of the time in Willowbrook it frosts late in the year after April 15 so make sure that you are prepared to protect your impatiens in the event of a surprise late frost.

USDA Zone Info for Willowbrook

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 Willowbrook

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