One of the best tools that you have as gardeners to help us determine 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.

By looking at the USDA zone info for Caribou it's a good idea to figure out when it's a good idea to plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant dahlias until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant dahlias 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 dahlias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlias may not have a chance to really do well. You can get started a little bit earlier by starting your dahlias indoors.

Last Frost Date

On average the last 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 an average and the actual date of last frost changes from year to year. Half of the time in Caribou last frost occurs after May 15 so make sure that you are prepared to protect your dahlias if you have 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.