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.

The earliest that you can plant napa valley fern in Lewiston can be determined by looking at the USDA zone info.

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 are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant napa valley fern in Lewiston is April. However, you really should wait until May 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 fully mature. You can get started a couple of weeks earlier by starting your napa valley fern indoors.

Last Frost Date

The average date of last frost is April 15 in Lewiston. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Lewiston is just an average and the actual date of last frost will vary from year to year. Half of the time in Lewiston you get surprised by a frost after April 15 so make sure that you are ready to cover your napa valley fern in the event of a surprise late frost.

USDA Zone Info for Lewiston

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Lewiston

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