The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Portland you can estimate when it's a good idea to plant napa valley fern by checking out the USDA zone info.

Planting Calendar for Napa Valley Fern

Frost tolerance for napa valley fern:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since napa valley fern do not do well in cold weather it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant napa valley fern in Portland 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 little bit earlier.

Last Frost Date

In Portland the average date of last frost happens on March 15. You should expect an average low temperature of 15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Portland is not always accurate and the actual date of last frost is different every year. Half of the time in Portland you get surprised by a frost after March 15 so make sure that you are prepared to cover your napa valley fern in the event of a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Portland

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