The USDA Zone info is a great tool for gardeners to help us estimate 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.

The first opportunity to plant bishop's weed in Caribou should be determined by checking out 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.

Bishop's Weed do well in cold which tells us that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant bishop's weed in Caribou is March. However, you really should wait until April 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 August. 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 few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Caribou. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Caribou and it is different every year. Half of the time in Caribou last frost occurs after May 15 so make sure that you are prepared to cover your bishop's weed in the event of a late frost.

USDA Zone Info for Caribou

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Caribou

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