One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

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

Planting Calendar for Polygonums

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

Since polygonums are not cold tolerant it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant polygonums in Salem 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. If you wait any later than that and your polygonums may not have a chance to grow to maturity. If you are starting your polygonums indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Salem the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Salem is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Salem you get a frost after April 15 so always be ready to cover your polygonums if you have one of those late frosts.

USDA Zone Info for Salem

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 Salem

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