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

By looking at the USDA zone info for Iron Mountain you will be able to determine when you can plant napa valley fern.

Planting Calendar for Napa Valley Fern

Frost tolerance for napa valley fern:	Not tolerant of frost.
When to plant:	After the last frost.

It's not a good idea to plant napa valley fern until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant napa valley fern 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 napa valley fern and expect a good harvest is probably August. Any later than that and your napa valley fern may not have a chance to really do well. If you are starting your napa valley fern indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Iron Mountain and it changes from year to year. Since half of the time in Iron Mountain last frost occurs after May 15 be ready to protect your napa valley fern in the event of 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.