Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's possible to plant bishop's weed by looking at the USDA zone info for Rockville.

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 cold which means that you can plant them a quite a bit earlier than other plants that might not handle the cold.

The earliest that you can plant bishop's weed in Rockville 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 fully mature. If you are starting your bishop's weed indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Rockville. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Rockville is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Rockville you get surprised by a frost after April 15 so make sure that you are prepared to cover your bishop's weed if you have a late frost.

USDA Zone Info for Rockville

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 Rockville

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