One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Portsmouth you should be able to determine when it's the best time 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.

You can plant asparagus a lot earlier in the year because they do well in 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. You probably don't want to wait any later than that or else your asparagus may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your asparagus indoors.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Portsmouth and it is different every year. Since half of the time in Portsmouth it frosts late in the year after April 15 be ready to cover your asparagus in the event of one of those late frosts.

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.