Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 bougainvillea in Caribou can be figured out by referring to the USDA zone info.

Planting Calendar for Bougainvillea

Frost tolerance for bougainvillea:	Not tolerant of frost.
When to plant:	After the last frost.

You can not plant bougainvillea until after the last frost because they do not do well in cold weather.

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

Since the USDA zone info for Caribou may not be accurate from year to year 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 make sure that you are ready to cover your bougainvillea 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.