One of the first steps you take when you are making a decision about 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 first chance to plant iresene in Caribou should be determined by checking out the USDA zone info.

Planting Calendar for Iresene

Frost tolerance for iresene:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since iresene are not cold tolerant you really should wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant iresene 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 iresene and expect a good harvest is probably August. If you wait any later than that and your iresene may not have a chance to grow to maturity. If you are starting your iresene indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Caribou is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Caribou you get a frost after May 15 so be sure to be ready to protect your iresene 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.