When to Plant Nasturtium in Portsmouth, NH

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Portsmouth you should be able to determine when it's the best time to plant nasturtium.


Planting Calendar for Nasturtium

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

Since nasturtium require warm weather it's necessary to wait until after all chance of frost has passed before you can plant them.

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

The earliest that you can plant nasturtium 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 nasturtium and expect a good harvest is probably August. Any later than that and your nasturtium may not have a chance to fully mature. If you are starting your nasturtium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Portsmouth is not always accurate the actual date of last frost changes from year to year. Since half of the time in Portsmouth you get surprised by a frost after April 15 be ready to cover your nasturtium in the event of 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.