Before planting it is a good idea to find your USDA Zone info to determine 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.

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

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 tells us that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant napa valley fern in Rockford 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. Any later than that and your napa valley fern may not have a chance to grow to maturity. 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 April 15 in Rockford. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Rockford is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Rockford you get a frost after April 15 be ready to cover your napa valley fern in the event of a surprise late frost.

USDA Zone Info for Rockford

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 Rockford

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