Cyrtomium, commonly known as holly fern, is a small group of 36 species that are native to Asia, Africa, and Oceania. Only four species are commonly available to gardeners, Cyrtomium falcatum, Cyrtomium fortunei, Cyrtomium macrophyllum, and Cyrtomium caryotideum. There is a movement afoot to merge the genus Cyrtomium with the genus Polystichum. While there are some species which straddle the line between the two genera, we’re just not comfortable with this merger, so we will retain the separate genera. The name Cyrtomium is derived from the ancient Greek word ‘kyrtoma’ meaning arch. The veins in the fronds branch from a mid-vein and then arch over and rejoin each other.
Holly ferns are known for their bold, tropical, evergreen foliage, which is in stark contrast to the soft-textured nature of most typical ferns. These tough and durable ferns that tolerate the worst of light and drought conditions make great additions to the low-maintenance woodland garden. Average to dryish soil moisture conditions are great for many of these adaptable ferns. At the northern end of their hardiness range, the foliage may become tattered during the winter months. If so, you can remove the foliage in late winter, just prior to the emergence of the new leaves.
Holly Fern Varieties
Cyrtomium caryotideum (Caryota Leaf Holly Fern) This Asian fern looks very different from the more commonly seen Cyrtomium falcatum, in fact, it looks like a Caryota palm leaf. The olive drab foliage consists of very large pinnae, which are attached five or so to each side of the stem. The end leaflet on each stem has a cool three-lobed look, almost like an Amur maple. A clump of this evergreen fern will eventually make a lovely 3' wide mound from a single rosette. (Hardiness Zone 7b-10b, at least)
Cyrtomium caryotideum ‘Sa Pa’ (Sa Pa Caryota Leaf Holly Fern) This amazing spore grown selection hails from a spore collection by Ozzie Johnson in Sa Pa, Vietnam and has much longer and more abundant small serrations and lobes along the margins of the pinnae. It produces beautiful deep green, glossy leaves that can obtain 2.5’ in length or more. (Hardiness Zone 7b-10b, at least)
Cyrtomium falcatum (Falcate Holly Fern) The easy-to-grow 4' wide x 18” tall, tough-as-nails clumps are composed of outward arching fronds of glossy evergreen leaves. Dry to typical garden soil is best. This is the most frequently grown species in the Southeast and is one of the easiest ferns to cultivate. A note of caution: in warmer zones this species may spread well-beyond the boundaries of your garden and become invasive. (Hardiness Zone 7a-10b, possibly colder)
Cyrtomium falcatum 'Butterfieldii' (Butterfield’s Holly Fern) The 18" long, glossy, dark evergreen fronds of Cyrtomium 'Butterfieldii' are easily recognizable by their very serrate, deeply toothed leaf margins. Each 18" tall by 3' wide clump has a truly unique appearance thanks to the serrate foliage... a great specimen fern. (Hardiness Zone 7a-10b, at least)
Cyrtomium falcatum ssp. littorale ‘Eco Korean Lace’ (Korean Lace Dwarf Holly Fern) This is an amazing dwarf subspecies of Cyrtomium falcatum, probably the one collected by Barry Yinger from Baengnyeongdo Island, Korea. It was only recently described (2017) from Japanese populations but we feel the material from Baengnyeongdo Island is probably that taxon. Whatever you call it, this choice fern for the woodland rock garden makes a small clump, eventually reaching 6" tall by 15" wide. The very thick, glossy green leaves make this an eye-catching specimen. It will tolerate a significant amount of heat and light and we have found it successful when grown in rockeries and rock walls in full sun here at JLBG. (Hardiness Zone 7a-9b, at least)
Cyrtomium fortunei (Fortune’s Holly Fern) This Asian holly fern has a much narrower and more upright frond with many more pinnae than the more common Cyrtomium falcatum. The species is amazingly variable and among our many collections are plants with olive colored foliage, deep green and even lime green with a blackish midrib. The 3' wide clumps of evergreen bold textured foliage make a great year-round backdrop to other deciduous woodland perennials. This is probably the hardiest of the bold tropical textured ferns. (Hardiness Zone 6a-9b, at least)
Cyrtomium fortunei 'China Ruffles' (China Ruffles Fortune’s Holly Fern) (syn HH-03CH038) This unusual selection of Cyrtomium fortunei comes from a 2003 Hans Hansen expedition to China. This clone was discovered at 4700' elevation in Tao Yuan, China. This unique form of Cyrtomium fortunei makes a 1' tall by 2' wide evergreen clump with fronds composed of narrow pinnae that are unusually ruffled and highlighted by a dark central stipe and a dark central leaf vein...very attractive! (Hardiness Zone 6a-9b guessing)
Cyrtomium lonchitoides (Spear-shaped Holly Fern) Cyrtomium lonchitoides is a little-known holly fern that hails from forests between 4,000' and 8,500' elevation in the Chinese provinces of Gansu, Guangxi, Guizhou, Henan, Sichuan, Xizang, and Yunnan. For us, Cyrtomium lonchitoides has developed into a lovely compact evergreen fern to 1' tall x 2' wide in our woodland garden. Well-drained soils are best since Cyrtomium lonchitoides often grows in the wild as a lithophyte (on rocks). Though similar in form to Fortune’s Holly Fern, this species is smaller and has narrower pinnae with even more pairs of pinnae (leaflets) that each have a sharp “tooth-like lobe” on the upper side at the base. (Hardiness Zone 6a-8b, at least)
Cyrtomium macrophyllum The bold textured, light green fronds arch outward to make a 2' wide clump that is semi-evergreen in most winters. Semi-evergreen means that it still has leaves in spring, but they look so rough that you'll probably want to cut them off. This species has few pinnae (leaflets) but each one is quite broad, and it makes a stunning specimen for the woodland garden. Easy to grow. (Hardiness Zone 7a-10b, possibly colder)