When to Plant Polygonums in Harvey, IL

One of the best tools that you have as gardeners to help us determine 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 Harvey you can estimate when it's possible to plant polygonums by reviewing 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.

Polygonums are not cold tolerant which tells us that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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 Harvey 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. If you are starting your polygonums indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Harvey and it changes from year to year. Since half of the time in Harvey there is a last frost after April 15 be ready to cover your polygonums if you have a surprise late frost.

USDA Zone Info for Harvey

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 Harvey

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