When to Plant Polygonums in Decatur, IL

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.

The earliest that you can plant polygonums in Decatur should be determined by reviewing the USDA zone info.


Planting Calendar for Polygonums

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

You really shouldn't plant polygonums until after all chance of frost has passed because they require warm weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant polygonums
Possibly ok, but a risky time to plant polygonums
Probably not a good time to plant polygonums

The earliest that you can plant polygonums in Decatur 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 fully mature. If you are starting your polygonums indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Decatur the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Decatur is just an average and the actual date of last frost changes from year to year. Since half of the time in Decatur last frost occurs after April 15 be ready to cover your polygonums if you have a late frost.

USDA Zone Info for Decatur

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 Decatur

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