Picking the Right Ferns

When I think of planting ferns I usually think of shady, moist conditions.  But that’s not all.  There are ferns that do well in dry conditions and some that can handle a fair amount of sun.  One aspect of fern selection I had not thought of much was soil pH (or acidity).  My only knowledge here was that maidenhair fern, Adiantum capillus-veneris, needed alkaline conditions, but that was about it.  (However, Northern maidenhair fern, A. pedatum, is less demanding, preferring neutral conditions.)  My eyes were opened a bit further when I read an article in Fine Gardening by C. Colston Burell on Hardy Native Ferns.  In it is a table listing light and soil tolerance of about 25 native ferns.   I thought that I now had a definitive decision making tool.  However, as I did some more research for this blog post I started finding conflicting information on what conditions particular species preferred.  One reason for the confusion may be the difference between ‘preferred conditions’ and ‘conditions tolerated.’  While some species are very particular about what they need to grow, others are more tolerant of variation.  Lacking a full understanding how growing conditions were measured and of what truly unacceptable conditions are, I am inclined to treat published growing conditions as more what you’d call guidelines than actual rules. 

With that in mind, the table got me to thinking about the ferns I had planted that were not doing very well.  Three particular ferns that are not excelling in my plantings are royal fern, cinnamon fern and hay-scented fern.  The soil in my area is neutral to alkaline and these struggling ferns are listed in Burell’s table as preferring acidic soils. 

The royal fern, Osmunda regalis, is in a moist shady spot.  I was hoping that this taller fern would form a diffuse back ground to highlight smaller plants planted in the foreground.  After three years it has not grown more than 6 inches tall and has only put out a few stems.  This year I will try transplanting over some ostrich ferns, Matteuccia struthiopteris, into that area.  These are listed as growing in alkaline conditions and they have a very strong vase shape, though they are visually more dense than royal ferns.

Ostrich fern grows to about 3' tall with a strong vase-shaped
habit, reaching full size by mid-spring.  Its preference
for neutral to alkaline conditions makes it a good choice
for foundation plantings.

The cinnamon fern, Osmunda cinnamomea, is doing somewhat better.  It’s planted in part sun with similar moist soil.  I was hoping that the light green fronds of the vise-shaped fern would stand out on the edge of a shrub border.  So far the plants are just holding on.  Perhaps here I could add some sulfur to make the soil just a bit more acid.  (That would also benefit the nearby hollies.)

These 2 cinnamon ferns were chosen for there bright green color and
vase-shaped form which contrasts with the darker green of the
hollies behind.  All of these plants would benefit from a bit more soil acidity.

The third fern that is under-performing my expectations is hay-scented fern, Dennstaedtia punctiloba.  My understanding was that this aggressive fern would grow just about anywhere.  That’s why I am using it in my vinca replacement project where the conditions are dry shade.  Three years in and only one clump has spread a little, and two others have died. 

These hay-scented ferns, growing in a gravel bed, are just unfurling
in mid-April in the Boston area.  They will grow to be about 2' tall.

Considering that my soil is pretty much neutral (6.8-7.2) I should avoid ferns that need acidic conditions and focus more on those that are happy with neutral conditions. 

Ferns suited to neutral to alkaline conditions include: ostrich fern, Matteuccia struthiopteris, marginal wood fern, Dryopteris marginalis, lady fern, Athyrium  filix-femina and sensitive fern, Onoclea sensibilis.  One uncommon fern I found growing in the woods was blunt-lobed cliff fern, Woodsia obtusa, which prefers alkaline conditions.

This cliff fern is growing on a east facing rocky slope.

Ferns that I have found noted as indifferent to soil pH are Christmas fern, Polystichum acrostichoides, and ebony spleenwort, Asplenium platyneuron.  These are both very common ferns on my property.

Christmas fern is evergreen and has a more relaxed upright habit. 
Even in January this fern looks pretty good.  

Ebony spleenwort is a smaller fern more useful as a ground
cover component than as a feature plant.  This specimen was
growing in full shade and was about 8" tall.  In sunnier locations
it stays closer to the ground.  Ebony spleenwort will grow on a
variety of soils whereas other species of spleenworts prefer
neutral to alkaline conditions.

Maybe it's best to proceed cautiously when there is a question.  If you’re uncertain, rather than doing a massive planting, put in one or two and see how they do. 

A Winter Walk

Seeing as we were having a spell of dry weather on New Year's day, I decided to take a walk through the woods to see what was happening.  Now that essentially all the leaves are gone there's a whole other world of things to see.  Instead of focusing on the foliage, trees can be recognized by their bark, branching patterns and leaf buds.  On the ground level the few evergreen grasses and perennials are easy to find.  In particular, the evergreen ferns jumped right out.  Following are some photos of plant features that I came across.

The buds of this 2 year old seedling are
smooth and reddish brown.

The first place I checked out were some tree seedlings that I identified in the vegetable garden last summer.  Since I already knew what they were I could learn about how they look in the off season and store that away for future reference.


The end bud of the Sycamore was smooth and pyramidal.  Kind of like those of ash trees, but the sycamore has a single false-end bud (not centered at the absolute end of the twig), while ashes have a terminal bud flanked by two smaller, opposite buds.   

Another tree that sprouted in the garden was an Eastern Cottonwood, Populus deltoides.  Here the bud end is true and the scales are visible.  To me the most notable feature is that the year-old wood looks like it has shrunken back. leaving the stem somewhat squarish with wings, or ridges along the corners. 

Cottonwoods are often considered rather messy trees.  This spring I will transplant it into a moist area of the meadow that I am clearing of invasives.

The  dry leaves on this American beech
make it easy to spot in the woods.

Moving into the woods a young American Beech caught my eye.  In the winter these can be recognized by their tendency to hold onto their leaves until the spring and by their smooth white bark.

Another tree that has smooth white bark is the American Hornbeam, Carpinus caroliniana.  While the beech has a smooth rounded trunk, The hornbeam's trunk is grooved, giving it a muscular or sinewy appearance.  Another way to distinguish these two white-barked trees is their leaf buds.  The buds of the hornbeam are small and dark brown while those of the beech are orangy-brown, long and pointed with many obvious scales.

Another tree with unique bark is the Hackberry.  Though highly variable many trees develop warty knobs and/or ridges that is easy to recognize.  Despite the unappealing name, the hackberry is a valuable wildlife plant, both as a butterfly host species and for producing a crop of 'sugarberries' in the fall for birds and small mammals.

The bark of the Hackberry is hard to miss.

Looking onto the ground plane I found several different evergreen grasses, which remain unknown.  More easily identified were the several species of evergreen ferns.  The most easily ID'ed was the Christmas fern.  This is a common species here growing mostly in shady moist areas.  

Christmas Fern is 'once-cut' and the pinna (leaf)
has a single lobe that makes it look like a boot.

A much smaller fern common here is the Ebony Spleenwort, Asplenium platyneuron.  This one is found in partly sunny location with average moisture.  Mine usually grow to about 6" long and hide in the undergrowth.

The frond of this Evergreen Wood Fern
appears to have been stepped on,
but otherwise looks pretty good.  

While poking around a steeply sloped area I found a fern that was new to me.  Unlike the previous two species this one was much frillier (thrice divided).  I took a bunch of photos and pulled out my fern ID books to come up with a name.  Turns out that I was an Evergreen Wood Fern, Dryopteris intermedia.  This is a common species in the eastern US, but just not that common to my piece of the woods.  It's relatively healthy green appearance in the middle of winter would make it a good addition to a home landscape.

When ID'ing ferns look on the bottom sides of the fronds for the sporangia or sori.
Their shape and location are distinctive for many species.

An unknown fern growing at the base of a tree.

There was one fern that I could not figure out.  It was small (3-4") and had fairly simple leaves (pinna).  It's grow in a gap between roots of a large tree.  I checked the underside of the frond for sporangia, but none to be seen.  I'll need to come back later in the spring to see how it develops.

I would appreciate any ideas on what this might be.

Underside of fronds shows no additional clues.

The last group of plants I checked on were some vines that I planted last summer.  My property is inundated with Japanese honeysuckle.  While I am trying to remove those I am also adding some native ones to fill the voids,  I put in a native Coral Honeysuckle along a fence in the spring.  It quietly grew to a span of over 6'.  Looking forward to seeing some blooms in the spring.  I also added some cultivars, 'Honey Coral' and 'Sulfurea'.  

Can see some flower buds forming on this Coral Honeysuckle.  OOPS, this is actually
Carolina jessamine, Gelsemium sempervirens.  I think it was a tag mix-up in the nursery.
It was covered with yellow blossoms in 2016.

The leaves of this Carolina Jasmine have turned red,
 but are holding on.

On an impulse I also picked up a Carolina Jasmine cultivar called 'Margarita'.  This species is hardy to zone 7, naturally occuring as far north as southeastern Virginia.  However, this 'Margarita' cultivar is good into zone 6.  So far it is holding onto its leaves.  This one may be too small to bloom come February, but I will be happy if it just survives and starts growing when the weather warms.

Getting Aquainted

View upstream toward Harper's Ferry, WV a few days before Hurricane Sandy.

We've been in the new house for a little over a month now and we are starting to get into a new rhythm.  We are about a mile from the Potomac River, near Harper's Ferry.  As the leaves are falling it is easier to see the landscape features on the grounds and also identify some of the plants that were previously inaccessible through the brush.

The woolly leaves of Sweet Everlasting are similar
to those of Pearly Everlasting (see below). 

As I was tramping through the less explored areas, one familiar plant that stood out for me was the annual, Sweet Everlasting, Pseudognaphalium obtussifolium.  This can be distinguished by its nearly pure white flowers, compared to the yellow-centered flowers of the similar looking Pearly Everlasting.

The flowers of Pearly Everlasting have yellow centers.

The reddish-brown stipe of Ebony Spleenwort
is not as rigid as those of Christmas Fern.

As I made my way into the ravine at the back of the property I saw some familiar Christmas Ferns growing in the shade.  I turned around and saw another similar looking fern that turned out to be Ebony Spleenwort, Asplenium platyneuron.  These are both 'once-cut' ferns with boot-shaped leaves (pinnae), but the spleenwort has a reddish brown stem (stipe) and is generally more delicate in appearance.

One of the projects I have in mind is to 'develop' a portion of the property as a meadow area.   I was planning on covering the area with cardboard (a material I have an ample supply of after unpacking) to kill off the existing lawn.  However, a good portion of this area has been going wild for a couple of years and, on closer examination, I have found many of the desired grasses already present.  Now I think I will take a different approach, rather than starting with a clean slate, I will augment the existing native species and edit out the invasives.  This will be a tedious job, but  it would be a shame to remove the indigenous gene pool and replace them with the same species from some other ecoregion.  Currently in this meadow to be there are a lot of Multiflora Rose.  There also appear to be some other rose species.  I will need to wait for some fresh growth to make a determination of which rose is which.  

Multiflora Rose can be identified by the comb-like stipules.
Most native roses less complex stipules.

Anyone familiar with this plant?

There are a number of wildflowers growing in this area.  One that was still in bloom in October is what I believe to be a species of Helianthus.  I would appreciate any thoughts as to which species this is.  Since there was only one plant in bloom, I did not want to generalize too much based on one (partial) flower.  I'm leaning toward Jerusalem Artichoke, H. tuberosus, but there are so many other possibilities.

Some of the native grasses that are well represented in this meadow area are Little Bluestem, Switch Grass, and Deer Tongue Grass.  In the deciduous woods there are many clumps of Spreading Sedge, Carex laxiculmis.

Little Bluestem comes into its glory in the fall
when the seedheads glow in the low sunlight

Deer Tongue Grass stands out among the other grasses in the sunny meadow with its relatively short, broad blades.  The plume-like seed heads are lost early in the season.  

Clumps of Spreading Sedge are scattered
through the moist deciduous woodlands.

Fall projects include clearing out some of the fallen trees and thinning the River Grape vines and other overgrown shrubs from around the trees.