Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant four o' clock in Naperville should be determined by using 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.

Since four o' clock are not cold tolerant it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant four o' clock in Naperville 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. You probably don't want to wait any later than that or else your four o' clock may not have a chance to grow to maturity. Starting your four o' clock indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Naperville. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Naperville is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Naperville there is a last frost after April 15 be ready to protect your four o' clock if you have a surprise late frost.

USDA Zone Info for Naperville

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 Naperville

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