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

The first opportunity to plant phlox in Iron Mountain should be estimated by referring to the USDA zone info.

Planting Calendar for Phlox

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

Phlox do ok in a little bit of cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant phlox 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 phlox and expect a good harvest is probably August. You probably don't want to wait any later than that or else your phlox may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your phlox indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Iron Mountain is just an average and the actual date of last frost will vary from year to year. Half of the time in Iron Mountain there is a last frost after May 15 so make sure that you are ready to cover your phlox 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.