One of the best tools that you have as gardeners to help us estimate 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.

It's possible to estimate when to plant polygonums by checking out the USDA zone info for River Grove.

Planting Calendar for Polygonums

Frost tolerance for polygonums:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since polygonums do not do well in cold weather you really should wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant polygonums in River Grove 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 grow to maturity. If you are starting your polygonums indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In River Grove the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for River Grove is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in River Grove you get surprised by a frost after April 15 be ready to cover your polygonums if you have one of those late frosts.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.