Thelypteris kunthii – Southern Shield Fern

Southern shield fern, Thelypteris kunthii or Dryopteris normalis, is an adaptable and easy to grow deciduous native fern.

An excellent fern for beginning gardeners, southern shield fern can survive drought if grown in the shade and even full sun if plenty of constant moisture is available. Southern shield fern is at home in wetlands.

Southern shield fern is aptly named, as it is native to every state in the southeastern United States. There is something about the heat and humidity of the deep south that allows it to prosper here.

Water needs are fairly high for Thelypteris kunthii so don’t plant this native fern in a habitually dry garden. Other than the need for moisture, southern shield fern is very tough. It can survive brutally tough winter conditions (to less than 0 degrees F. for brief periods). It is generally recognized as being winter hardy zones 6b-9. Fall foliage is an attractive bronze color. It spreads easily but is not aggressive or invasive.

Southern shield fern is a great fern for beginning gardeners.

It is recognized by a number of genus and species names, with Thelypteris kunthii, Thelypteris normalis, and Dryopteris normalis being the most common. Regarding common names, it is also called wood fern, normal shield fern, river fern, and Kunth’s maiden fern*.

It grows to 36″ tall. Ferns like plenty of organic matter in the soil. Amend soil generously wherever you plant ferns. Thelypteris kunthii will appreciate the nutrients and perhaps most importantly you will help avoid compacted clay conditions that are the death of so many perennials and shrubs.

Poor drainage is acceptable, but compacted soil will not allow the roots to breathe nor grow properly.

Thelypteris kunthii’s fronds tend to grow in all kinds of haphazard directions. Southern shield fern looks like many people’s idea of what a fern should look like, with fronds arching too and fro. This is not a neat fern with a pronounced crown and rosette of fronds. It is a bit of a wayward grower and one has to find charm in this fact.

*Thelypteris kunthii is named in honor of Carl Sigismund Kunth, a German botanist active in the first part of the 19th century. He is credited with being among the first botanists to focus their studies on the flora of America.