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

The first chance to plant sorrel in Caribou can be estimated by checking out the USDA zone info.

Planting Calendar for Sorrel

Frost tolerance for sorrel:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Sorrel are moderately cold tolerant which means that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant sorrel 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 sorrel and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sorrel may not have a chance to grow to maturity. Starting your sorrel indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Caribou. In the coldest months of winter you should expect an average low temperature of -30°F.

It's important to remember that USDA zone info for Caribou is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Caribou last frost occurs after May 15 be ready to protect your sorrel in the event of a surprise 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.