Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Portland you can estimate when you can plant bishop's weed by referring to 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.

Since bishop's weed do well in cold you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant bishop's weed in Portland 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 really do well. Starting your bishop's weed indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Portland the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Portland may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Portland it frosts late in the year after April 15 so always be ready to protect your bishop's weed in the event of one of those late frosts.

USDA Zone Info for Portland

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Portland

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