The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 estimate when to plant polygonums by referring to the USDA zone info for Carol Stream.

Planting Calendar for Polygonums

Frost tolerance for polygonums:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant polygonums until after the last frost because they require warm weather.

The earliest that you can plant polygonums in Carol Stream 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 polygonums and expect a good harvest is probably August. You probably don't want to wait any later than that or else your polygonums may not have a chance to grow to maturity. You can get started a little bit earlier by starting your polygonums indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Carol Stream. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Carol Stream may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Carol Stream you get surprised by a frost after April 15 be ready to protect your polygonums if you have one of those late frosts.

USDA Zone Info for Carol Stream

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 Carol Stream

You may be interested in your other planting guides for Carol Stream.