Here at Plant Delights Nursery and Juniper Level Botanic Garden, we are always trialing ferns that we feel are under-represented in the nursery trade. Below are a few of our favorites that have proven to be suitable for our Zone 7b conditions.
Sitobolium (Dennstaedtia) – Hay-scented Ferns
Dennstaedtia are a genus of ferns from the family Dennstaedtiaceae, commonly known as hay-scented ferns. Dennstaedtia was once quite an expansive genus ranging nearly worldwide but has now been split into segregate genera. The temperate species that are growable in our climate are now mostly placed in the genus Sitobolium. The hay-scent is produced by brushing against or crushing the fronds which will emit an odor that smells like a fresh cut lawn full of Sweet Vernal Grass (Anthoxanthum odoratum) in spring.
"A truly deer-resistant fern"
Sitobolium (Dennstaedtia) punctilobula (Hay-scented Fern) This is a traveler to be sure. The aggressively rhizomatous nature of this plant make it only appropriate for covering a very large space. The one truly redeeming factor is that deer absolutely refuse to eat it. A home we owned in Roaring Gap, NC had an enormous herd of deer that visited the landscape and ate everything, and I mean everything (prickly-pears, Agave, you name it) EXCEPT the Hay-scented Fern. This species forms enormous patches in the woodlands of the Appalachians and does not grow as well outside of areas with cool nighttime weather. (Hardiness Zone 3a – 8a)
Microlepia – Rigid Lace Ferns
Microlepia is a genus whose name is derived from the Greek ‘micros’ and ‘lepis’ for ‘a small scale’ referring to the size and shape of the indusium. It consists of 70 species that are native to tropical areas around the world. The primary species that is in cultivation in warm temperate climates is Microlepia strigosa. The glossy green fronds have a truly unique appearance. We have found this to be a marvelous fern in our trials, but one which needs a soil that is slightly acidic, thriving in soils ranging from pH 6.0-6.8.
Microlepia strigosa (Rigid Lace Fern) (aka: Dennstaedtia strigosa) Imagine a non-rampant, brighter, and darker green hay-scented fern and you've got Microlepia strigosa. This Japanese native (Kyushu, Shikoku, and also surrounding islands) makes a wide-spreading clump of up to 3' long arching leaves. Above 10ºF, the foliage stays evergreen but below that, it is tardily deciduous. (Hardiness Zone 7b-10b, possibly colder)
Microlepia strigosa f. crispa ‘Shishi’ (Shishi Rigid Lace Fern) (aka: Dennstaedtia strigosa) Microlepia strigosa forma crispa is a compact form with congested green pinnae. Each 18" tall by 2' wide clump makes an attractive, lacy specimen. Above 10ºF, the foliage stays evergreen but below that, it is tardily deciduous. (Hardiness Zone 7b-10b, possibly colder)
Microlepia strigosa ‘Macfaydenii’ (Macfayden’s Rigid Lace Fern) Microlepia 'MacFaddeniae' was discovered in the garden of Mrs. MacFadden, and first published in 1957 by Conrad Morton in the American Fern Society Journal, so it's taken quite a while to get this into the commercial trade. The tardily deciduous (evergreen in warmer climates) Microlepia strigosa 'MacFaddeniae' forms a slowly spreading patch to 3' wide in 5 years, composed of 2' long, narrow, arching, deeply lobed fronds. (Hardiness Zone 7b-10, possibly colder)
Paesia – Lace Fern
Paesia is a small genus of 11 species found mostly in the southern hemisphere, most notably in New Guinea. The one species in this genus that thrives here in the Southeast is native to New Zealand and makes a superb, low, slow-spreading groundcover.
"Paesia scaberula makes a superb, low, slow-spreading groundcover."
Paesia scaberula (Scented Lace Fern) We have long been fans of Scented Lace Fern, but its popularity and slow rate of spread leaves us rarely with any to share. Paesia scaberula is native to New Zealand where it can be found growing on dry, rocky cliffs, and in open areas. Although Paesia scaberula grows for us in light shade, it really thrives in sun, where it forms a deciduous, rhizomatous patch to 3' wide in 2 years. Our plants produce 1' tall fronds that are incredibly lacy...one of the most finely divided ferns we've grown. In its native haunts the leaves can easily reach twice this size and we’re not sure if our plants are truly dwarf or simply responding to the dramatically different climate here in the Southeast. The foliage of Paesia scaberula also contains terpenes, which smell delicious when crushed or pelted by rain showers. Imagine a fast-growing fern with leaves that look like a rabbit's foot fern, and you've got the idea.
We encourage everyone to give hay-scented ferns and lace ferns a try and to be more conscious of the textures and forms that ferns can add to your garden. Also, our ferns are nursery propagated from spores, not harvested from the wild. You can read more about why this matters and all about our mission of ex-situ conservation over at jlbg.org.