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

The USDA zone info for Marengo can be used to figure out when it's possible to plant bishop's weed.

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 tells us 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 Marengo 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 grow to maturity. You can get started a couple of weeks earlier by starting your bishop's weed indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Marengo. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Marengo and it will vary from year to year. Half of the time in Marengo there is a last frost after April 15 so be sure to be ready to protect your bishop's weed if you have one of those late frosts.

USDA Zone Info for Marengo

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 Marengo

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