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 first opportunity to plant aubretia in Caribou should be determined by referring to the USDA zone info.

Planting Calendar for Aubretia

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

Since aubretia are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant aubretia 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 aubretia and expect a good harvest is probably August. Any later than that and your aubretia may not have a chance to grow to maturity. Starting your aubretia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Caribou. In the coldest months of winter you should expect an average low temperature of -30°F.

Just be sure to remember that USDA zone info for Caribou is an average and the actual date of last frost is different every year. Half of the time in Caribou it frosts late in the year after May 15 so always be ready to protect your aubretia 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.