Adiantum capillus-veneris ‘Bermuda Run’ is looking exceptional in the garden this fall. Actually, it looks exceptional most of the year for us. Until the temperatures drop below 12 degrees F, this amazing fern remains evergreen. This fern has a huge native range, being found on every continent except Antarctica.
Adiantum capillus-veneris, along with a couple of pteris fern species are often found growing in mortar cracks in many of the Southeast coastal cities and adjacent tropical islands. It is thought that some of these populations may have been spread along the early trade routes. This particularly dense form is our collection from the mortar walls on Bermuda. The same species is native to North Carolina, but only in a solitary population. Winter hardiness is Zone 7b-10b.
Looking particularly lovely in the garden is the elegant fern, Dryopteris affinis ssp. affinis. The semi-evergreen golden-scaled male fern from Europe is among the easiest and most beautiful ferns we grow, yet when we offer it through the nursery, it’s always one of the worst sellers. We struggle to figure out mysteries like this when you have a fern that grows equally as well in acid or alkaline soils, and grows the same in the Pacific Northwest as it does the hot, humid Southeast US. Winter hardiness is Zone 4a-8b.
It’s not unusual for ferns to have sex in the wild, even with other species in the same genus. It is, however, unusual for them to have meaningful sex with ferns of an entirely different genus. Such an odd occurrence recently happened in the greenhouses of Louisiana’s James Georgusis.
One night, possibly after a wild Mardi Gras party, a willing Phlebodium got it on with a crested tongue fern of the genus Pyrrosia. The result was a new genus of fern, x Phlebosia. It was adopted and given the cultivar name, ‘Nicolas Diamond’. At least the parents had the good sense to sexually stay within the same family, Polypodiaceae
We planted our first specimens in the garden this February, and so far, it’s growing well. The key will be to see how much winter hardiness it has…fingers crossed. Both parents are pictured below the new hybrid.
Here’s a fun textural image from the woodland garden, featuring Hydrangea quercifolia ‘Little Honey’, Farfugium japonicum ‘Aureomaculatum’, and Athyrium ‘Ocean’s Fury’. Off to the left side are three more ferns, Dryopteris x celsa, Adiantum capillus-veneris, and Ctenitis subglandulosa.
We’ve long loved the fern genus, Pteris (pronounced terrace), but struggled for years to find any that were winter hardy here in Zone 7b. That changed with our 1996 Chinese expedition to Yunnan Province, and later a subsequent expedition by gardening friends to Sichuan Province. On both trips, high elevation collections of Pteris vittata were made that were much more cold hardy than anything from previous introductions. Both introductions have thrive here since the late 1990s. What we also love is that these ferns thrive in full, baking sun. Even now, in mid-July, these ferns look absolutely amazing in the gardens. Plant Delights currently has one of these amazing selections for sale. Hardiness is Zone 7b-10b.
While doing some local botanizing recently, we ran across this fascinating form of our native Christmas fern, Polystichum acrostichoides. Not only was it more compact than any others in the area, with more “orderly” fronds, but it also showed none of the typical terminal spore production that would be expected this time of year. Since this was from a future development site, the plant was rescued, and is now at JLBG under evaluation. The second photo is more typical plant for the species for comparison, growing at JLBG.
One of the most Jurrasic-looking plants we grow is the North American native Ostrich fern. If you moved here from “up north” and brought some of this fern with you, chances are it failed miserably. As a rule, Ostrich fern, Matteuccia struthiopteris, hates our summer temperatures.
Fortunately, back in the mid-1980s, retired UNC-Charlotte botany professor, Larry Mellichamp picked up a heat tolerant form from Powell’s Nursery in Princeton, NC, which he promptly introduced into the trade as Matteuccia ‘The King’. Without this incredible introduction, gardens in south would not have this amazing fern in their gardens.
This is a spreading fern that prefers average to wet soils, so allow plenty of room for it to spread. Below is a patch thriving at JLBG.
One of our favorite ferns is the Lady fern hybrid, Athyrium ‘Ocean’s Fury’. Created in Pittsboro, NC by plantsman Thurman Maness, this patented gem was offered for years through wholesale channels, but sales were not strong enough, so the sole producer discontinued it. So often, great patented plants suddenly become unavailable if sales don’t warrant.
In Europe, any grower can petition the PVR office to request permission to propagate such protected plants, but no such program exists in the US. Fortunately, Thurman has generously granted us permission to propagate his amazing introduction and make it available. That said, division is a very slow way to make ferns available, but since this hybrid between Athyrium filix-femina and Athyrium nipponicum is sterile, it’s our only option.
Looking good in the garden this week is the amazing fern, Dryopteris x australis. This rare fern is a US native…despite the confusing name, hailing from only a few scattered locations from Virginia west to Arkansas. In reality, the name “australis” means from the south. This splendid specimen grows in both sun and shade, and tolerates both wet and dry soils. Hardiness is Zone 5a-9b.
We often talk about the amazing group of hardy asparagus ferns, so here we go again with a few that are looking particularly great now.
The first image is our dwarf selection of Asparagus cochinchinensis ‘So Fine’. This is our new dwarf selection from our original collection from Korea’s Mt. Chuwang. Hardiness is Zone 4b-8b, at least.
Asparagus tenuifolius ‘Vodice’ has proven to be an amazing garden specimen with a tight compact habit. This is our collection from Vodice, Croatia. It’s amazing that this incredible species is completely absent from gardens. We have no idea about winter hardiness, but would expect Zone 5/6 at least.
The amazing Asparagus sprengeri ‘Graham’s Cracker’ just continues to amaze us. This dwarf selection of the hanging basket asparagus fern from NC plantsman Graham Ray, has been reliable for years in Zone 5b, without the benefit of mulch or any other protection. We find it a superb textural contrast for bolder foliaged perennials.
Looking great in the JLBG gardens is the amazing Cyrtomium fortunei ‘China Ruffles’. This superb spore strain is from an original introduction by Michigan plantsman, Hans Hansen, who made the spore collection in 2003 in Sichuan, China. Hardiness is Zone 6-9.
If you’re a nursery, and you’d like to offer ferns, the plants at your disposal are somewhat limited. A large majority of ferns sold in America are still sadly dug from the wild. When you see a catalog listing primarily these ferns together…usually an very inexpensive prices, you can be pretty much assured they were dug from the wild: Osmunda regalis (royal fern), Osmunda cinnamomea (Cinnamon Fern), Polystichum acrostichoides (Christmas Fern), Matteuccia Matteuccia struthiopteris (Ostrich fern), Adiantum pedatum (Maidenhair fern), Athyrium filix-femina (lady fern), and Onoclea sensibilis (Sensitive Fern). These ferns are often sold bareroot, to save the nursery the expense of having to pot the collected plants, many of which are so large, they won’t fit in small containers.
The other majority of ferns in the market are produced by tissue culture, either by a couple of labs in Florida, one in Texas, and one in Holland. Without the amazing work of these labs, the fern selections available to homeowners would be limited to the wild collections. Even with their amazing work, these labs must focus on well-known ferns that sell in very large numbers.
While we make use of the lab offerings, we also made a commitment over 30 years ago to grow many of our own ferns from spores. Outside of a few small fern specialists, there are few nurseries who grow their own ferns from spores, since this is the most costly and time consuming option. The reason we do this is so that we can offer fern species and selected forms that are otherwise unavailable.
Below is a quick summary of how the process works. Fern spores (fern equivalents of seed) are collected through the summer, and are dried in paper envelopes until they separate from the foliage. They are then sown in pots with potting soil that is sterilized here, and then sealed in ziploc bags. The spore takes from 1 month to 6 months to germinate. Once the spores germinate, they are ready to have sex…a process that is reversed from more modern evolved flowering plants.
To assist the ferns have sex, we gently add water to the newly germinated sporelings, since ferns (other than desert ferns) only have sex while they are swimming. The water is swirled around to mimic the feel of a whirlpool, then the bags are then resealed, and put in the dark where they are subjected to a near constant montage of Barry White music.
Within a few weeks, tiny fern fronds begin to emerge. At this point, the ziploc bags are opened to allow the humidity to equalize with the ambient air. After another couple of weeks the pots are removed from the ziploc bags. If the spore were viable and cleaned well without contamination, and if germination was good, there will be up to several hundred plants per pot.
After a few weeks, the sporelings are transplanted into a cell pack flat. Here they grow out for another few months until they are ready to be planted into our 1 qt. pots, in which they will be sold. In all, it’s about an 18 month process, and a good bit of labor. We’re really quite passionate about our fern collection at JLBG, which the visiting British Fern Society declared one of the largest/most diverse in the world. We hope you find the results worthwhile.
The dainty rock garden fern, Woodsia polystichoides has just emerged in the garden. The spores for this were shared by one of our Russian gardening friends from his collection on the Sakhalin Islands. For those who don’t follow history, the Sakhalin Islands were another of Russia’s many conquests, this from a 2 week war with Japan in 1945, when neither country was behaving neighborly. What a shame that countries aren’t run by gardeners. Hardiness is Zone 4-7b.
Since ferns are one of the groups on which we focus our ex-situ conservation efforts, we have collected a huge number of species and selections from around the world. One that has continually frustrated us is the miniature rock fern, Asplenium trichomanes. Although this small gem is native to every continent except Antartica, we have struggled to keep it alive.
In our travels, we have collected it from Europe to Africa, but have also managed to kill all of those collections in the garden. Since our first attempt in 2004, we have now killed Asplenium trichomanes 16 times. We believe, however, in the late JC Raulston’s mantra, “Unless you are killing plants, you aren’t growing as a gardener.” The key is how many times do you continue to try before giving up?
We’re pretty stubborn as long as we feel we keep learning from each failure. Our latest accession of this species, which came as spores from Russia’s south coast, is actually thriving in our crevice garden, where the pH is north of 8.0. It seems that the crevice habitat is the answer.
Just out in the garden in early January and wanted to share photos of a few of our favorite evergreen ferns that would rather not be growing in the ground. In our garden, these are all growing within a few feet of each other.
Each of these ferns are epiphytes, which grow attached to a tree, or lithophytes, which grow attached to a rock. None of these ferns actually need soil to grow, since they get their food and water from the atmosphere and accumulated organic debris. Epiphytes, however, don’t get nutrients from their host plant…only physical support.
All epiphytic ferns thrive in hanging baskets, especially the spaghnum-lined type, since this most closely mimics their natural preferences. In our case, we are a bit colder than their native haunts, so for us, we force these ferns to reside in the ground since that gives them a bit more protection during severe winter temperatures. The key for epiphytes to survive in the ground is to have very loose, organic soils and always plant them on a steep slope.
Neolepisorus fortunei ‘Green Ribbons’ is our 2017 introduction of a Chinese native epiphytic fern.
Pyrrosia lingua ‘Hiryu’ is also an epiphytic fern, native to Japan.
Lastly is Polypodium vulgare ‘Ulleung Island’. Instead of being an epiphyte, this evergreen fern is a lithophyte. Lithophytes are classified as either epilithic (growing across the rock surface) or endolithic (growing in cracks or crevices). Since we found this in the wild, growing across the surface of a giant rock, this fern is an epilithic lithophyte…say that three times fast. This is our 1997 collection from an island, far off the coast of South Korea.
We hope you’ll explore these unique ferns in your garden.
We always love it when unexpected garden hookups yield unexpected results, and such was the case recently when, under the cover of darkness, two of our holly ferns took a liking to each other. The result of this conjugal interlude is our first hybrid of Cyrtomium fortunei x Cyrtomium falcatum, that we’ve named Cyrtomium x fortatum Spornication. The habit of the hybrid is intermediate between both parents. Now, we’ve just got to figure out how to get it propagated in order to share.
We love the evergreen holly fern in all it’s species and forms. Cyrtomium falcatum ‘Butterfieldii’ is looking absolutely stupendous in the garden this month. This easy to grow shade lover glistens all winter with its glossy foliage with fancy serrated edges. Hardiness is Zone 7a-8b.
We love the tardily deciduous Ctenitis subglandulosa ‘Hoshizaki’, which remains looking great in the garden as we pass the winter solstice. This truly elegant fern came to us from fern guru, Judith Jones, who got it from California fern guru, Barbara Jo Hoshizaki. The airy texture and ease of growth make this a fern we wouldn’t garden without. Sadly, we offered this Asian native (Bhutan through China) once through Plant Delights and very few people purchased one, so we had to discard the remaining crop…ouch! So very sorry you missed a true gem. Hardiness is Zone 7a-8b (guessing).
Another genus of ferns that we just adore are the bamboo ferns of the genus coniogramme. We’ve grown these amazing gems for two decades, and after all that time are still in love. Although these woodland ferns are deciduous, they are tardily so, so they still look quite fresh into mid-November. Here are a couple of favorites, photographed this week.
At the top is the texturally fascinating Coniogramme intermedia ‘Shishi’ from Japan, and below this is our 2006 introduction of the Chinense native Coniogramme emeiensis ‘Golden Zebra’. We rate both of these as winter hardy from Zone 7b and warmer.
We love ferns of all types, but especially the single-leaf types. Our clump of the Chinese Lepisorus macrosphaerus really stands out in the fall and winter garden. In the wild, most lepisorus grow on rocks or tree trunks, but most we’ve grown have adapted well to growing in the soil. They tend to thrive better when growing on slopes, and in well-drained soils.
One of our favorite of the US native (Central Texas) desert ferns is Pellaea ovata. Here is our clump in the crevice garden looking quite nice this week. This is scheduled to return to the Plant Delights catalog in January. Hardiness should be at least Zone 7b and south.
Looking superb this week is our great native fern, Thelypteris kunthii (southern shield fern) So what is a kunth? In fact, this fern gets its name from German taxonomist, Carl Sigismund Kunth (1788 – 1850). Kunth was one of the first people to categorize North American plants, mostly from the collections of German botanists, Humboldt and Bonpland. Thelypteris kunthii was named in his honor in 1967, long after Kunth’s death, by American botanist Conrad Morton (1905-1972). In our gardens, it thrives in both light shade and full sun…an amazing plant.
Cyrtomium macrophyllum is looking particularly fabulous this year. This is a little-grown holly fern with a wide range from India to Southeastern China that can be found at elevations from 2,500-8,000′. The bold textured fronds arch outward to make a 2′ tall x 2′ wide clump that is semi-evergreen in most winters. It seems as if we will get good spore set this year, which may mean another offering since the last time PDN had it to share in 2003.
We live in an age where many plastic products are vilified, but every now and then, we find a reason to embrace the texture of plastic. Such was the case in 2008, when we visited The Missouri Botanic Garden. Walking through one of their greenhouse, I spotted an odd holly fern, planted in the middle of a large mass of Cyrtomium falcatum. The foliage appeared much thicker and more glossy than any of the other plants. The staff was kind enough to share a piece, which we subsequently named Cyrtomium ‘Plasticity’. We theorize it is probably a ploidy mutant with an extra set of chromosomes that would account for the extra thickness and glossiness. Here is a photo from the gardens this week, where it has become a favorite.
Arachnioides standishii is one of our favorite garden ferns. This particular collection comes from Japan’s Mt. Daisen. The common name is Upside down fern since the leaves appear to be attached inverted. Production is always challenging since spore don’t ripen until after Christmas. The foliage remains evergreen until temps drop below 10 degrees F. Hardiness is Zone 4-8.
Here are a couple of fern images from the garden yesterday. First is our giant painted fern, Athyrium ‘Godzilla’, which can reach 6′ wide x 3′ tall. To avoid chlorophyll shed in the garden, it’s best planted a far distance from Hosta ‘Mothra’ or Hosta ‘Rhodan’.
For 2015, Plant Delights is pleased to introduce several new ferns from our trial program. Athyrium niponicum ‘Thrill Seeker’ is one of two dwarf compact crested Japanese painted fern selections from a five year joint effort between us and our friend Hans Hansen of Walters Gardens.
The second of these crested selections is Athyrium ‘Joy Ride’…quite distinct from Athyrium ‘Thrill Seeker’ when seen side by side.
Another unique fern that hasn’t been offered before is the 5′ tall, prehistoric looking Pronephrium penangianum. This amazing fern has been fabulous in our trials, but we doubt it will tolerate winters much colder than 0 degrees F.