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 first chance to plant polygonums in Oregon City can be determined 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 has passed.

You should not plant polygonums until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant polygonums in Oregon City 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 really do well. You can get started a few weeks earlier by starting your polygonums indoors.

Last Frost Date

In Oregon City the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 15°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Oregon City and it can change quite a bit from year to year. Half of the time in Oregon City last frost occurs after March 15 so make sure that you are prepared to protect your polygonums if you have a surprise late frost.

USDA Zone Info for Oregon City

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 Oregon City

You may be interested in your other planting guides for Oregon City.