Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Willoughby you can figure out when it's the best time 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.

Since polygonums require warm weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant polygonums in Willoughby 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 grow to maturity. You can get started a few weeks earlier by starting your polygonums indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Willoughby. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Willoughby and it will vary from year to year. Half of the time in Willoughby you get a frost after April 15 so be sure to be ready to protect your polygonums in the event of a surprise late frost.

USDA Zone Info for Willoughby

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Willoughby

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