The USDA Zone info is a great tool for gardeners to help us determine 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.

You will be able to estimate when to plant asparagus fern by looking at the USDA zone info for Portland.

Planting Calendar for Asparagus Fern

Frost tolerance for asparagus fern:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant asparagus fern until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant asparagus 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 asparagus fern and expect a good harvest is probably August. Any later than that and your asparagus fern may not have a chance to fully mature. You can get started a few weeks earlier by starting your asparagus fern indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Portland. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Portland is not always accurate the actual date of last frost will vary from year to year. Half of the time in Portland it frosts late in the year after March 15 so make sure that you are prepared to cover your asparagus fern if you have one of those late frosts.

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.