Before planting it is a good idea to find your USDA Zone info to determine 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.

A common way of estimating when it's a good idea to plant polygonums is to use the USDA zone info for Johnstown.

Planting Calendar for Polygonums

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

Polygonums do not do well in cold weather which means that it's important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant polygonums in Johnstown 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 really do well. 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 Johnstown the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Johnstown is an average the actual date of last frost is different every year. Half of the time in Johnstown you get surprised by a frost after April 15 so make sure that you are ready to protect your polygonums in the event of one of those late frosts.

USDA Zone Info for Johnstown

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Johnstown

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