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.

A way of getting a good idea when you can plant hosta is to consult the USDA zone info for Caribou.

Planting Calendar for Hosta

Frost tolerance for hosta:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Hosta do ok in moderate cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant hosta 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 hosta and expect a good harvest is probably August. Any later than that and your hosta may not have a chance to really do well. You can get started a couple of weeks earlier by starting your hosta indoors.

Last Frost Date

The average date of last frost is 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 changes from year to year. Half of the time in Caribou last frost occurs after May 15 so make sure that you are ready to protect your hosta in the event of 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.