The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when to plant oregano is to look at the USDA zone info for Iron Mountain.

Planting Calendar for Oregano

Frost tolerance for oregano:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Oregano do well in moderate cold which tells us that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant oregano 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 oregano and expect a good harvest is probably August. Any later than that and your oregano may not have a chance to really do well. Starting your oregano 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 Iron Mountain. It might get as low as -30°F during the coldest months of winter.

It's important to remember that USDA zone info for Iron Mountain is an average and the actual date of last frost is different every year. Half of the time in Iron Mountain you get a frost after May 15 so be sure to be ready to cover your oregano if you have one of those late frosts.

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.