Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's a good idea to plant alyssum is to use the USDA zone info for Caribou.

Planting Calendar for Alyssum

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

Alyssum tend to make it in cold weather which means that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant alyssum 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 alyssum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your alyssum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your alyssum indoors.

Last Frost Date

On average all chance of 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 will vary from year to year. Half of the time in Caribou last frost occurs after May 15 so just be sure to be ready to protect your alyssum in the event of 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.