Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Portsmouth you will be able to estimate when it's a good idea to plant asparagus.

Planting Calendar for Asparagus

Frost tolerance for asparagus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Asparagus can survive in pretty solid cold which tells us that you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant asparagus in Portsmouth is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant asparagus and expect a good harvest is probably September. If you wait any later than that and your asparagus may not have a chance to fully mature. You can get started a few weeks earlier by starting your asparagus indoors.

Last Frost Date

The average date of last frost is March 15 in Portsmouth. In the coldest months of winter you should expect an average low temperature of 10°F.

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 last frost occurs after March 15 so just be sure to be ready to protect your asparagus in the event of a surprise late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

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

Plants to Grow in Portsmouth

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