One of the best tools that you have as gardeners to help us figure out 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.

The best time to plant polygonums in College Place should be figured out by checking out 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 you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant polygonums in College Place 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 fully mature. You can get started a couple of weeks earlier by starting your polygonums indoors.

Last Frost Date

The average date of last frost is April 15 in College Place. In the coldest months of winter you can expect an average low temperature of 0°F.

Since the USDA zone info for College Place is just an average the actual date of last frost changes from year to year. Half of the time in College Place it frosts late in the year after April 15 so be sure to be ready to cover your polygonums if you have a late frost.

USDA Zone Info for College Place

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in College Place

You may be interested in your other planting guides for College Place.