Before planting it is a good idea to find your USDA Zone info to determine your garden 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 chance to plant peonies in Caribou should be estimated by reviewing the USDA zone info.

Planting Calendar for Peonies

Frost tolerance for peonies:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant peonies just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant peonies in Caribou is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant peonies and expect a good harvest is probably August. If you wait any later than that and your peonies may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your peonies indoors.

Last Frost Date

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

Since the USDA zone info for Caribou is just an average the actual date of last frost will vary from year to year. Since half of the time in Caribou there is a last frost after May 15 be ready to protect your peonies 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.