The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when you can plant polygonums by referring to the USDA zone info for Morris.

Planting Calendar for Polygonums

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

You can not plant polygonums until after the last frost because they do not do well in cold weather.

The earliest that you can plant polygonums in Morris 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 few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Morris. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Morris is an average the actual date of last frost is different every year. Since half of the time in Morris it frosts late in the year after April 15 be ready to protect your polygonums if you have one of those late frosts.

USDA Zone Info for Morris

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 Morris

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