When to Plant Amaranthus in Portsmouth, NH

One of the first steps you take when you are figuring out 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.

The first chance to plant amaranthus in Portsmouth should be determined by using the USDA zone info.


Planting Calendar for Amaranthus

Frost tolerance for amaranthus: Not tolerant of frost.
When to plant: After the last frost.

Since amaranthus require warm weather you need to wait until after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant amaranthus
Possibly ok, but a risky time to plant amaranthus
Probably not a good time to plant amaranthus

The earliest that you can plant amaranthus 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 amaranthus and expect a good harvest is probably August. Any later than that and your amaranthus may not have a chance to really do well. Starting your amaranthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portsmouth and it changes from year to year. Since half of the time in Portsmouth last frost occurs after April 15 be ready to cover your amaranthus 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.