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

In Portsmouth you can figure out when it's the best time to plant ornamental grasses by using the USDA zone info.

Planting Calendar for Ornamental Grasses

Frost tolerance for ornamental grasses:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Ornamental Grasses are barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

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

The last month that you can plant ornamental grasses and expect a good harvest is probably August. You probably don't want to wait any later than that or else your ornamental grasses may not have a chance to really do well. Starting your ornamental grasses indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portsmouth. You can expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Portsmouth and it can change quite a bit from year to year. Since half of the time in Portsmouth last frost occurs after April 15 be ready to protect your ornamental grasses if you have one of those late frosts.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Portsmouth

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