The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Caribou you should be able to determine when it's a good idea to plant arabis.

Planting Calendar for Arabis

Frost tolerance for arabis:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant arabis quite a bit earlier in the year because they do well in cold.

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

Last Frost Date

The average date of last frost is May 15 in Caribou. You can expect an average low temperature of -30°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Caribou and it changes from year to year. Half of the time in Caribou it frosts late in the year after May 15 so be sure to be ready to cover your arabis if you have 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.