When to Plant Schizanthus in Portsmouth, NH

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.

You will be able to figure out when it's a good idea to plant schizanthus by referring to the USDA zone info for Portsmouth.


Planting Calendar for Schizanthus

Frost tolerance for schizanthus: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

It's not a good idea to plant schizanthus until after all chance of frost has passed because they require warm weather.

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

The earliest that you can plant schizanthus 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 schizanthus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your schizanthus may not have a chance to grow to maturity. Starting your schizanthus 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.

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 a frost after April 15 so always be ready to protect your schizanthus if you have a late frost.

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.