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.

The USDA zone info for Elmhurst can be reviewed to determine when to plant four o' clock.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You can not plant four o' clock until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant four o' clock in Elmhurst 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. If you wait any later than that and your four o' clock may not have a chance to fully mature. If you are starting your four o' clock indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Elmhurst is just an average the actual date of last frost changes from year to year. Since half of the time in Elmhurst last frost occurs after April 15 be ready to protect your four o' clock in the event of one of those late frosts.

USDA Zone Info for Elmhurst

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 Elmhurst

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