One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Oregon should be looked at to figure out when you can plant bishop's weed.

Planting Calendar for Bishop's Weed

Frost tolerance for bishop's weed:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since bishop's weed do well in cold you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant bishop's weed in Oregon is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant bishop's weed and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bishop's weed may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your bishop's weed indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Oregon. In the coldest months of winter you should expect an average low temperature of -20°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Oregon and it can change quite a bit from year to year. Half of the time in Oregon last frost occurs after April 15 so make sure that you are ready to cover your bishop's weed in the event of a surprise late frost.

USDA Zone Info for Oregon

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 Oregon

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