The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's a good idea to plant bishop's weed in Washington by using the USDA zone info.

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.

Bishop's Weed do well in quite a bit of cold which means that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant bishop's weed in Washington 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. Any later than that and your bishop's weed may not have a chance to fully mature. You can get started a few weeks earlier by starting your bishop's weed indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Washington. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for Washington is just an average the actual date of last frost is different every year. Since half of the time in Washington you get surprised by a frost after March 15 be ready to cover your bishop's weed in the event of a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Washington

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