One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Caribou should be used to determine when it's possible to plant doronicum.

Planting Calendar for Doronicum

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

You can plant doronicum a little bit earlier in the year because they do well in moderate cold.

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

Last Frost Date

On average all chance of frost has passed is on May 15 in Caribou. You can expect an average low temperature of -30°F in the coldest months of winter.

Remember that USDA zone info for Caribou is not always accurate and the actual date of last frost is different every year. Half of the time in Caribou last frost occurs after May 15 so make sure that you are ready to protect your doronicum if you have one of those late frosts.

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.