One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Keene it's a good idea to determine when it's the best time to plant polygonums.

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 it is necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant polygonums in Keene 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. Any later than that and your polygonums may not have a chance to grow to maturity. You can get started a little bit earlier by starting your polygonums indoors.

Last Frost Date

In Keene 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.

It's important to remember that USDA zone info for Keene is an average and the actual date of last frost changes from year to year. Since half of the time in Keene there is a last frost after April 15 be ready to protect your polygonums in the event of a surprise late frost.

USDA Zone Info for Keene

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 Keene

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