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

In Portsmouth you can figure out when it's a good idea to plant asparagus fern by checking out the USDA zone info.

Planting Calendar for Asparagus Fern

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

Asparagus Fern require warm weather which means that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant asparagus fern in Portsmouth 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. You probably don't want to wait any later than that or else your asparagus fern may not have a chance to really do well. Starting your asparagus fern indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portsmouth. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Portsmouth may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Portsmouth you get a frost after April 15 so just be sure to be ready to cover your asparagus fern in the event of a surprise late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Portsmouth

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