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.

The USDA zone info for Winnetka should be reviewed to determine when to plant four-o-clock flower.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After the last frost.

Four-o-clock flower do not do well in cold weather which tells us that it is important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant four-o-clock flower in Winnetka 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 flower and expect a good harvest is probably August. If you wait any later than that and your four-o-clock flower may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Winnetka. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Winnetka may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Winnetka you get a frost after April 15 so always be ready to protect your four-o-clock flower if you have a late frost.

USDA Zone Info for Winnetka

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 Winnetka

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