The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 Island Lake can be used to estimate 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 should not plant four o' clock until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant four o' clock in Island Lake 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 couple of weeks earlier by starting your four o' clock indoors.

Last Frost Date

In Island Lake the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Island Lake may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Island Lake it frosts late in the year after April 15 be ready to cover your four o' clock in the event of a surprise late frost.

USDA Zone Info for Island Lake

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 Island Lake

You may be interested in your other planting guides for Island Lake.