One of the best tools that you have as gardeners to help us determine 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.

The USDA zone info for Iron Mountain can be read to figure out when it's the best time to plant aubretia.

Planting Calendar for Aubretia

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

Aubretia are very cold tolerant which tells us that you can get them planted much earlier than other plants that might not handle the cold.

The earliest that you can plant aubretia 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 aubretia and expect a good harvest is probably August. If you wait any later than that and your aubretia may not have a chance to fully mature. Starting your aubretia indoors is a great way to get them started a couple of weeks 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.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Iron Mountain and it will vary from year to year. Half of the time in Iron Mountain there is a last frost after May 15 so just be sure to be ready to cover your aubretia 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.