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

The first chance to plant four o' clock in Willowbrook can be figured out by looking at the USDA zone info.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Four O' Clock are not cold tolerant which tells us that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant four o' clock 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 four o' clock and expect a good harvest is probably August. Any later than that and your four o' clock may not have a chance to fully mature. You can get started a little bit earlier by starting your four o' clock indoors.

Last Frost Date

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

Since the USDA zone info for Willowbrook is just an average the actual date of last frost will vary from year to year. Half of the time in Willowbrook there is a last frost after April 15 so always be ready to cover your four o' clock if you have one of those late frosts.

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.