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.

A way of getting a good idea when it's the best time to plant bishop's weed is to examine the USDA zone info for Washington.

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 ok in a bit of cold which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

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. If you wait any later than that and your bishop's weed may not have a chance to really do well. You can get started a few weeks earlier by starting your bishop's weed indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Washington. You can expect an average low temperature of 10°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Washington and it is different every year. Half of the time in Washington there is a last frost after March 15 so make sure that you are ready to protect your bishop's weed if you have 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.