The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when to plant bishop's weed by using the USDA zone info for Hillsboro.

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 other plants that might not handle the cold.

The earliest that you can plant bishop's weed in Hillsboro 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 is on April 15 in Hillsboro. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Hillsboro is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Hillsboro you get a frost after April 15 be ready to cover your bishop's weed if you have one of those late frosts.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Hillsboro

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