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

You should be able to figure out when it's possible to plant napa valley fern by referring to the USDA zone info for Litchfield.

Planting Calendar for Napa Valley Fern

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

Since napa valley fern are not cold tolerant it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant napa valley fern in Litchfield 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. Starting your napa valley fern indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Litchfield the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Just be sure to remember that USDA zone info for Litchfield may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Litchfield it frosts late in the year after May 15 be ready to cover your napa valley fern in the event of a late frost.

USDA Zone Info for Litchfield

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 Litchfield

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