One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Iron Mountain can be read to estimate when it's a good idea to plant browallia.

Planting Calendar for Browallia

Frost tolerance for browallia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Browallia do not do well in cold weather which tells us that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant browallia 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 browallia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your browallia may not have a chance to fully mature. If you are starting your browallia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Iron Mountain is just an average the actual date of last frost will vary from year to year. Half of the time in Iron Mountain you get a frost after May 15 so make sure that you are prepared to protect your browallia in the event of a surprise 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.