The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant jerusalem artichokes in Portsmouth should be figured out by referring to the USDA zone info.

Planting Calendar for Jerusalem artichokes

Frost tolerance for jerusalem artichokes:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Jerusalem artichokes do well in moderate cold which means that you can plant them earlier than other frost tender plants.

The earliest that you can plant jerusalem artichokes 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 jerusalem artichokes and expect a good harvest is probably September. You probably don't want to wait any later than that or else your jerusalem artichokes may not have a chance to really do well. If you are starting your jerusalem artichokes indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on 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 is not always accurate the actual date of last frost will vary from year to year. Half of the time in Portsmouth it frosts late in the year after March 15 so make sure that you are ready to protect your jerusalem artichokes if you have a 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.