One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 Normal you can figure out when it's a good idea to plant polygonums by using the USDA zone info.

Planting Calendar for Polygonums

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

You should not plant polygonums until after the last frost because they require warm weather.

The earliest that you can plant polygonums in Normal 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. If you wait any later than that and your polygonums may not have a chance to really do well. You can get started a few weeks earlier by starting your polygonums indoors.

Last Frost Date

On average the last frost is on April 15 in Normal. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Normal is just an average the actual date of last frost will vary from year to year. Half of the time in Normal there is a last frost after April 15 so always be ready to cover your polygonums in the event of a surprise late frost.

USDA Zone Info for Normal

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 Normal

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