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.

The first chance to plant tomatos in Portsmouth can be estimated by using the USDA zone info.

Planting Calendar for Tomatos

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

Tomatos are not cold tolerant which tells us that it is necessary to wait until it warms up after the last frost before you can plant them.

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

Last Frost Date

On average the last frost is on April 15 in Portsmouth. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Portsmouth is just an average the actual date of last frost is different every year. Half of the time in Portsmouth you get surprised by a frost after April 15 so make sure that you are prepared to cover your tomatos 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.