Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of figuring out when it's possible to plant napa valley fern is to refer to the USDA zone info for Douglas.

Planting Calendar for Napa Valley Fern

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

Napa Valley Fern do not do well in cold weather which means that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant napa valley fern in Douglas 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. If you wait any later than that and your napa valley fern may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your napa valley fern indoors.

Last Frost Date

The average date of last frost is May 15 in Douglas. You should expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for Douglas is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Douglas you get a frost after May 15 so make sure that you are prepared to protect your napa valley fern if you have a surprise late frost.

USDA Zone Info for Douglas

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 Douglas

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