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

A common way of making a decision about when it's possible to plant bishop's weed is to consult the USDA zone info for Swarthmore.

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 are one of those plants that can tolerate quite a bit of cold weather which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant bishop's weed in Swarthmore 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 grow to maturity. If you are starting your bishop's weed indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Swarthmore. You can expect an average low temperature of 0°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Swarthmore may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Swarthmore there is a last frost 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 Swarthmore

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Swarthmore

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