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 using the USDA zone info for Grand Forks it's possible to figure out when it's possible 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 all chance of frost has passed.

Since napa valley fern do not do well in cold weather you must wait until after the last frost has passed before you can plant them.

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

Last Frost Date

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

Keep in mind that USDA zone info for Grand Forks is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Grand Forks there is a last frost after May 15 be ready to cover your napa valley fern if you have a late frost.

USDA Zone Info for Grand Forks

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 Grand Forks

You may be interested in your other planting guides for Grand Forks.