The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Coal City you should be able to estimate when it's the best time to plant polygonums.

Planting Calendar for Polygonums

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

Polygonums require warm weather which tells us that it's important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant polygonums in Coal City 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 fully mature. 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 Coal City. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Coal City is an average the actual date of last frost will vary from year to year. Half of the time in Coal City it frosts late in the year after April 15 so make sure that you are prepared to protect your polygonums in the event of one of those late frosts.

USDA Zone Info for Coal City

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 Coal City

You may be interested in your other planting guides for Coal City.