Before planting it is a good idea to find your USDA Zone info to figure out 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 way of estimating when it's a good idea to plant napa valley fern is to use the USDA zone info for Williston.

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 is necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant napa valley fern in Williston 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 fully mature. If you are starting your napa valley fern indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Williston. In the coldest months of winter you should expect an average low temperature of -30°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Williston and it changes from year to year. Since half of the time in Williston there is a last frost after May 15 be ready to cover your napa valley fern if you have one of those late frosts.

USDA Zone Info for Williston

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 Williston

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