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.

In Haverhill you can figure out when it's possible to plant polygonums by using the USDA zone info.

Planting Calendar for Polygonums

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

You really shouldn't plant polygonums until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant polygonums in Haverhill 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 really do well. You can get started a little bit earlier by starting your polygonums indoors.

Last Frost Date

The average date of last frost is April 15 in Haverhill. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Haverhill is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Haverhill there is a last frost after April 15 be ready to cover your polygonums in the event of a late frost.

USDA Zone Info for Haverhill

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Haverhill

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