One of the first steps you take when you are estimating your gardening schedule is find your 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.

A way of estimating when it's a good idea to plant periwinkles is to use the USDA zone info for Libertyville.

Planting Calendar for Periwinkles

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

It's probably a bad idea to plant periwinkles until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant periwinkles in Libertyville 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. Any later than that and your periwinkles may not have a chance to fully mature. Starting your periwinkles indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Libertyville is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Libertyville it frosts late in the year after April 15 be ready to protect your periwinkles if you have a surprise late frost.

USDA Zone Info for Libertyville

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 Libertyville

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