One of the first steps you take when you are estimating your gardening schedule is find your 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.

By reviewing the USDA zone info for Decorah it's a good idea to determine when it's a good idea to 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 has passed.

You really shouldn't plant napa valley fern until after the last frost because they require warm weather.

The earliest that you can plant napa valley fern in Decorah 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. You probably don't want to wait any later than that or else your napa valley fern may not have a chance to grow to maturity. Starting your napa valley fern 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 Decorah. In the coldest months of winter you should expect an average low temperature of -25°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Decorah and it is different every year. Half of the time in Decorah last frost occurs after May 15 so just be sure to be ready to protect your napa valley fern if you have a late frost.

USDA Zone Info for Decorah

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Decorah

You may be interested in your other planting guides for Decorah.