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.

In Schiller Park you can estimate when to plant periwinkles by looking at the USDA zone info.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since periwinkles do not do well in cold weather it is necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Schiller Park 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 really do well. 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 Schiller Park. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Schiller Park and it changes from year to year. Since half of the time in Schiller Park there is a last frost after April 15 be ready to protect your periwinkles in the event of a surprise late frost.

USDA Zone Info for Schiller Park

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 Schiller Park

You may be interested in your other planting guides for Schiller Park.