One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when it's a good idea to plant bougainvillea is to examine the USDA zone info for Iron Mountain.

Planting Calendar for Bougainvillea

Frost tolerance for bougainvillea:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since bougainvillea require warm weather you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant bougainvillea in Iron Mountain 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. Any later than that and your bougainvillea may not have a chance to really do well. You can get started a couple of weeks earlier by starting your bougainvillea indoors.

Last Frost Date

The average date of last frost is May 15 in Iron Mountain. It might get as low as -30°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Iron Mountain and it is different every year. Half of the time in Iron Mountain it frosts late in the year after May 15 so make sure that you are prepared to cover your bougainvillea if you have a late frost.

USDA Zone Info for Iron Mountain

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 Iron Mountain

You may be interested in your other planting guides for Iron Mountain.