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

You should be able to determine when you can plant periwinkles by referring to the USDA zone info for Kankakee.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably a bad idea to plant periwinkles until after the last frost has passed because they require warm weather.

The earliest that you can plant periwinkles in Kankakee 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 periwinkles and expect a good harvest is probably August. You probably don't want to wait any later than that or else your periwinkles may not have a chance to grow to maturity. Starting your periwinkles 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 Kankakee. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Kankakee is just an average the actual date of last frost is different every year. Since half of the time in Kankakee last frost occurs after April 15 be ready to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Kankakee

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 Kankakee

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