When to Plant Fennel in Portsmouth, NH

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to figure out when you can plant fennel by referring to the USDA zone info for Portsmouth.


Planting Calendar for Fennel

Frost tolerance for fennel: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Since fennel do well in cold you can plant them quite a bit earlier in the year than other frost tender plants.

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

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

The last month that you can plant fennel and expect a good harvest is probably September. You probably don't want to wait any later than that or else your fennel may not have a chance to fully mature. Starting your fennel indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Remember that USDA zone info for Portsmouth may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Portsmouth it frosts late in the year after April 15 so make sure that you are prepared to protect your fennel 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.