When to Plant Rudbeckia in Portsmouth, NH

One of the first steps you take when you are making a decision about 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 USDA zone info for Portsmouth can be read to estimate when it's possible to plant rudbeckia.


Planting Calendar for Rudbeckia

Frost tolerance for rudbeckia: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

Since rudbeckia are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than other frost tender plants.

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

The earliest that you can plant rudbeckia 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 rudbeckia and expect a good harvest is probably September. If you wait any later than that and your rudbeckia may not have a chance to really do well. If you are starting your rudbeckia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. In the coldest months of winter you should 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 will vary from year to year. Half of the time in Portsmouth you get a frost after April 15 so make sure that you are ready to cover your rudbeckia 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.