One of the best tools that you have as gardeners to help us estimate 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 should be looked at to determine when you can plant violas.

Planting Calendar for Violas

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

Violas do well in cold which tells us that you can plant them much earlier than more sensitive plants.

The earliest that you can plant violas in Iron Mountain 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 violas and expect a good harvest is probably August. You probably don't want to wait any later than that or else your violas may not have a chance to grow to maturity. If you are starting your violas 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. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Iron Mountain is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Iron Mountain you get surprised by a frost after May 15 so always be ready to cover your violas 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.