One of the first steps you take when you are determining your gardening schedule is find your 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 earliest that you can plant black eyed susans in Caribou can be estimated by referring to the USDA zone info.

Planting Calendar for Black Eyed Susans

Frost tolerance for black eyed susans:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since black eyed susans are not cold tolerant you have to wait until after the last frost when the weather gets warmer before you can plant them.

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

The last month that you can plant black eyed susans and expect a good harvest is probably August. If you wait any later than that and your black eyed susans may not have a chance to grow to maturity. Starting your black eyed susans indoors is a great way to get them started a little bit 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.

Since the USDA zone info for Caribou is not always accurate the actual date of last frost will vary from year to year. Half of the time in Caribou there is a last frost after May 15 so make sure that you are prepared to cover your black eyed susans in the event of 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.