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

In Iron Mountain you can estimate when you can plant ageratum by referring to the USDA zone info.

Planting Calendar for Ageratum

Frost tolerance for ageratum:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Ageratum are not cold tolerant which means that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant ageratum 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 ageratum and expect a good harvest is probably August. If you wait any later than that and your ageratum may not have a chance to fully mature. If you are starting your ageratum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Iron Mountain. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Iron Mountain is not always accurate the actual date of last frost changes from year to year. Half of the time in Iron Mountain last frost occurs after May 15 so be sure to be ready to protect your ageratum 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.