Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant polygonums in Hillsboro should be estimated 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 has passed.

Polygonums are not cold tolerant which tells us that you must wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant polygonums in Hillsboro 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 fully mature. 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 Hillsboro the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Hillsboro is not always accurate the actual date of last frost will vary from year to year. Half of the time in Hillsboro last frost occurs after March 15 so be sure to be ready to protect your polygonums if you have a late frost.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Hillsboro

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