Ferns of Spring

The Winterthur garden provides not only wonderful spring color but also amazing details. The unfurling fronds of ferns are just one example of that. Even at this young stage, it is easy to identify certain ones. It is also a great time to think about how you might use them in your landscape. There are ferns that can provide either an extensive groundcover or an architectural focal point. Below are images of just a few that are unfolding now.

Ostrich fern, Matteuccia struthiopteris, is the predominant fern on the March Bank. Given a moist, shady area, it will happily spread by sending out rhizomes. Great if you have a large area to cover and it will readily come through Japanese pachysandra as seen below. It also combines well with the early bulbs of snowdrop, winter aconites and glory-of-the-snow that have already flowered on the March Bank. Ostrich fern is one of our tallest ferns, sometimes reaching 3’ in ideal settings.

Ostrich fern on the March Bank, late April.


Ostrich Fern is deciduous and it bears it spores on a separate frond, the two brown stalks shown here. These stalks persist through the winter and can be used in floral/Yuletide arrangements.

Ostrich fern

If you would like a tall fern but don’t have the spreading space for ostrich fern then cinnamon fern, Osmunda cinnamomea, is an excellent choice. It can reach 3 feet and will stay in place. Because it is deciduous and later to leaf out, it is also a good companion with Japanese pachysandra and late winter/early spring flowering bulbs.

Cinnamon Fern at Reflecting Pool


It can be identified at this early stage by the silver hair on the young fronds. Later, its cinnamon-colored spores add interest and are a key identification feature.

Cinnamon fern

Cinnamon fern with spores – late May















Royal fern, Osmunda regalis, is another fern to consider if you are looking for a non-aggressive, tall fern. Its unique structure adds contrast to other ferns and perennials. Like the other ferns listed here, royal fern is native to North America and will do best in moist soil.  It is sometimes called the flowering fern because of the appearance of it spores.


Royal fern in late April

Royal fern with spores in June














Lady fern, Athyrium filix-femina is a deciduous slow spreading fern that will reach about 2 feet. The stems can be green or red. Specific cultivars such as ‘Lady in Red’ will guarantee that you purchase one with red stems. Lady fern is a good choice if you would like a groundcover fern but one that won’t take over.

Lady fern in April with foliage of winter aconites

Lady Fern cv. Lady in Red


Christmas fern, Polystichum acrostichoides, is an evergreen fern. For ferns, that means its leaves will stay green through the winter and then start to die back in spring, as the new leaves are unfolding. You can either leave the old foliage and let the new fronds cover them or remove them if you prefer a tidier appearance. Christmas ferns are one of the best choices for heavy shade areas.

Christmas fern – late April

Christmas fern- note last year’s leaves


These are just a few of the fabulous ferns at Winterthur. They are all easy to grow and are readily available from nurseries.

The hori hori, often referred to as a “soil knife”, is a must-have garden tool.  First implemented in Japan, the tool can be described as a cross between a knife and a garden trowel.  It has a heavy, steel blade that is sharp on one edge and serrated on the other, with an overall shape that is slightly concave.  The word hori means “to dig” in Japanese.  The tool, in fact, is good for digging and so much more.  It can be used for weeding, planting, transplanting, removing plants, dividing perennials, sod cutting, cutting roots, loosening up root bound plants, planting bulbs, cutting twine, and cutting open bags of potting soil.  You get the idea!  With a large, comfortable handle the hori hori is designed to be used with one hand but can accommodate both hands when extra leverage is needed, such as when prying plants from the ground. With the use of an accompanying sheath, the tool is completely portable and within easy reach. The rust-resistant blade promises years of tough use in any garden setting.  I use this tool more than any other hand tool, as a horticulturist at Winterthur as well as in my home garden.

When managing the natural lands, I’ve found it’s almost like a strategy game.  Which areas need the most attention right now?  Which will need attention in 2 weeks?  In 3 months? Right now, in spring, I always have a few things on my plate.  After mowing the meadows, I usually turn my attention to the woodlands.  With our beautiful native spring ephemerals blooming in the woods, it’s a good time to figure out what doesn’t belong.  Without fail, one of my least favorite invasives always rears its head: Garlic Mustard!

Garlic Mustard (Alliaria petiolata) is a broadleaf biennial in the mustard family native to Europe and Asia, but has happily made a home here in woodlands, road edges, and shaded floodplains.  It’s easily identifiable from the garlicky smell of the plant, round, slightly toothed leaves, and white, 4-petaled (cruciform) flowers that shoot up from the basal rosette in April-May.  While the basal rosette of leaves is present year round, the flower shoot is specific to second year plants, and is present April- June.  The plant can reach up to 3 feet tall, and the seed pods are slender capsules typical of the mustard family called siliques.

Garlic Mustard with native Virginia Bluebells

Garlic Mustard with native Virginia Bluebells

Visible- round, toothed leaves and cruciform, white flowers

So, why do I have so much dislike for this plant?  Well it all comes down to ecology.  Garlic Mustard has a mechanism called allelopathy.  Basically, this means that the plant emits a chemical from its roots that disturbs the natural soil chemistry.  This prevents native plants from growing, native seeds from germinating, and encourages more growth of Garlic Mustard.  Slowly, it can decrease the natural diversity of native plants in a wooded ecosystem.  When a monoculture of Garlic Mustard occurs, it can lead to poor soil nutrient cycling and soil health decline, as well as a decline in the diversity of animals and insects that rely on native plants to survive.

Fortunately, this nasty plant is most effectively controlled by hand pulling!  For me, this time of year before the plant goes to seed is the ideal time to pull this plant aggressively.  I like to pull the plant from the base as close to the soil as I can get, and gently pull it out of the ground.  Especially after a rain, it comes right out- roots and all!  A little shake to knock off excess soil, and it’s into the weeding bucket.  Be sure to go at a nice steady pace.  Too fast, and you may inadvertently break the plant at the root since the main tap root usually juts sharply to one side.  This can lead to re-sprouting later in the season.

Main root juts to the right

At this point in the development of the plant, I can usually compost it without issue.  If composting isn’t an option, and I have to leave the plants behind, I’ll take my bunch of pulled plants and prop it up against a tree with the roots in the air so that the plants dry out and die without re-rooting.

Roots in the air to prevent re-rooting

If the plant has any seed capsule development at all, I will bag the plant and throw it away.  These seed capsules can still mature and spread seed- even after it’s been pulled!  Because the seeds can persist in the soil for a long time, this is a process I’ve had to repeat in various woodlands throughout the property for a few years.  But every year, I notice the decline in the Garlic Mustard population!  It’s the long game with Garlic Mustard, but one worth the effort.

If you’d like to know more about this invasive plant, or other invasive species in DE, you can go to the Delaware Invasive Species Council website!

This blog comes out on the eve of what would have been our 6th annual Daffodil Day; a Saturday set aside in mid-April to celebrate the daffodils planted during H.F. du Pont’s lifetime. Though some varieties may be found planted within garden areas such as the Quarry, March Bank and Sycamore Hill, the wider displays are naturalized in the fields alongside the garden, lining the front drive and in the cutting garden, an area off the beaten path where flowers would be picked for fresh displays in the house.

The daffodils at Winterthur are older varieties (this should not be to anyone’s surprise!) some dating back to the late 1800’s and early 1900’s
Unlike what we might do in our own home gardens, H.F. did not just open up a catalog, choose a few dozen cultivars and plant them. He used the same scrupulous eye in the creation of the daffodil beds as he did with the rest of the flowering combinations throughout the garden. He set up trial beds where he would observe the color, timing and persistence of the flowers over several years before placing them out in the garden, making sure to group “like with like” meaning daffodils that shared the same flowering time, beds that contained only a single variety within, and harmonious shades next to one another. The countless flowering displays and vignettes throughout the garden are all the result of an impassioned “head gardener” with a skillful eye.

One of my favorite things to do during daffodil season is to encourage visitors to follow directional white arrows and venture out into the meadow to walk among the daffodils, seeing the varieties up close and viewing the whole display and the garden from a vantage point that is different from the norm. Since that is not available to visitors this year, I will do my best to bring it to you. I have taken photos of the many varieties and ones that I might be a little partial toward (creative license!)

The daffodils greet you virtually now but look forward to seeing you live next spring! Enjoy the tour.

Daffodils along the Front Entrance drive.

White daffodils and clouds against the blue sky.

Daffodils with the Needle’s Eye folly in the background.

Daffodils in Browns Meadow with cherries in the distance.

Another long view into the garden toward the Mirrored Folly.

Daffodils near the sycamore.

Daffodil beds below Brick Overlook on Sycamore Hill.

Carpet of daffodils flanked by fragrant viburnum leading down to the Sundial garden

Now for a few closeups! I am partial to orange cups as well as small cup varieties but threw in some fun doubles, too.

Daffodil with spring beauty carpet below.

The buds on this cultivar are just as attractive.

A very large trumpet in Browns Meadow.

I will end with a video of the planting along the front drive. There are many many sounds of nature accompanying it; songbirds, spring peepers, Canada geese, so turn on the volume for the full experience!

Story Time in Enchanted Woods, a family program that shares the joy of reading while cultivating an interest and appreciation for nature in our youngest guests at Winterthur, may be on pause but the inspiration from the selected books can still be shared.  I anticipated reading, Bloom by Deborah Diesen, a story about spring bulbs, this week, perfectly timed with the bloom of hundreds of thousands of daffodils in the Winterthur Garden.  The book highlights a parent and child who planted bulbs together in the autumn and the excitement surrounding the emergence of the bulbs in the spring.  Planting bulbs is a fun activity for kids; from selecting which daffodils to plant, to digging the little individual holes, and placing the bulbs “pointy side up.”  Planting bulbs is easy to accomplish but does take a little planning.

Daffodils at my home.

Daffodil growers are taking orders now for the bulbs that will be shipped and planted this fall.  One of my favorite sources is Brent and Becky’s Bulbs.  Kids will love looking through their catalog or scrolling through their website at all of the different daffodils, as much as gardeners do.  Gardeners know that daffodils are classified into thirteen different divisions such as trumpet, cyclamineus, and jonquilla.  Kids will be delighted to find big ones, mini ones, fruity smelling ones, colorful ones, and ones with fun names.  Let the kids pick a favorite or a few and plan to plant the bulbs together this fall.  Each year the daffodils will return, providing spring bloom as well as a cherished memory of the time spent together in the garden.  For some extra fun, plan for the kids to enter their daffodil in our Children’s Daffodil Show at next year’s Daffodil Day at Winterthur.










Children’s Daffodil Show on Daffodil Day

As I mentioned in my blog “Coronet Cuts”, the arboriculture and natural lands teams at Winterthur are now one super power team! As I continue to further my knowledge on natural lands topics, we’ve started looking into artificial cavity creation for nesting birds. One specific species we are interested in making habitat for is the Eastern Screech Owl.


The eastern screech owl’s native range includes northern Delaware and more than half of the United States, all the way to the Rocky Mountains. They feed on small animals, nest in cavities, and prefer forested areas near a stream or river. They nest in cavities that already exist, they will not dig their own cavities. The owls tend to use natural cavities such as old woodpecker holes, and cavities enlarged by rot, fungus and other wildlife. Populations are steady in the United States but the garden staff of Winterthur are always looking for ways to encourage native species to find a home on the property.


Artificial cavity creation is a practice that is starting to be used more and more in the crossover industry of arboriculture and wildlife management. Many studies are proving just how successful these created cavities really are. Some completed studies show that artificial cavities have more natural thermal properties than that of nesting boxes and log hollows, meaning creating the cavity in a tree better mimics a natural cavity. Owls will be more likely to use a created cavity in a dead tree or snag than a nesting box if they have the choice.


The US Forest Service has had much success creating artificial cavities. They’ve been creating nesting habitat for the endangered red-cockaded woodpecker in the southern United States. This species has very specific habitat requirements and the forest service has been successful in creating those habitats to help increase the numbers of woodpeckers.


Here at Winterthur we are going to attempt our first artificial cavity creation this summer. The site will be in Duck Pond Woods, in a 40 foot snag (a tree that died but the trunk was left standing). The plan is to carve the cavity at about 30 feet above the ground. The dimensions of the cavity will be 14 inches tall, 10 inches deep, and around 12 inches wide. The entrance hole will be 3 inches in diameter located about 10 inches from the base of the cavity. These dimensions will ensure the owls are as comfortable as possible and will hopefully encourage them to frequent the site.  


Once we complete the cavity we plan to monitor the site from a distance. It will be impossible to stop other birds or wildlife from taking the cavity over as their home, which we understand and have already accepted. We feel that at least trying to set up the right habitat for certain species is worth it. I have included some photos of other projects around the country. Once completed I plan to follow up with pictures of Winterthur’s first artificial cavity!

Photo courtesy of fs.usda.gov

Step by step artificial cavity Photo courtesy of www.sciencedirect.com

Photo and drawing courtesy of “Tree Care for Birds” article taken from ISA Arborist News

In January 2019, the Winterthur arboriculture team and natural lands team joined together to create one super power team now cleverly called-the Arboriculture and Natural Lands Team! We oversee hundreds of acres of forests, meadows, streams, ponds, and miles of trails throughout all of Winterthur.

To help me better connect with the team I have been attempting to further my knowledge on natural lands topics. One topic that has caught my interest is the use of coronet cuts when pruning in our outlying areas. You are probably thinking “this guy has lost his mind, he’s just making up words”. Nope! A coronet cut is a real thing-it’s a pruning technique that is considered to be a type of natural fracturing. Coronet cuts are intended to mimic jagged edges usually seen on broken branches following storm damage or other limb failure.

This practice is very popular in the United Kingdom. It became popular because of the many “ancient trees” the UK has. This pruning practice has allowed them to extend the life of their prized ancient trees. Due to risk of structures and passersby, this practice is typically only used in old windrows, pastures, forest edges and other low risk areas.

Some of the pros of using this pruning method is to allow a tree to compartmentalize a wound naturally. If a limb needs to be removed for whatever reason I can lessen the impact on the tree by using this type of cut. It allows the tree to deal with the wound naturally as if the tree had lost the limb in a storm. Nature has cared for itself for millennia without human help- sometimes nature does it best! Another pro is wildlife. Wildlife loves crevasses, cavities, and hollow spots. By using coronet cuts, the amount of habitat can be increased within the management area.

One con of the coronet cut is aesthetics. The cuts are not the most attractive to the untrained eye. They tend to look messy and unprofessional. Another long term con is, as the tree naturally compartmentalizes the area where this treatment was used, the limb can become unstable with decay which can increase risk of future failure. This is why I would recommend this practice only be used in areas where that risk can be tolerated like open fields, forests, and other out of the way areas.

This pruning method is very difficult to perfect. It takes a well trained and experienced arborist to perform proper coronet cuts. If this method is something that you think would work at your home, please be sure to consult a professional arborist first. Ask your chosen professional if they or anyone on their staff has experience performing coronet cuts. It’s crazy to think how hard it is to prune a limb, just to make it look like it broke off naturally. Here at Winterthur I have started using this method on some of our outlying areas. It hasn’t been pretty, but it is coming along. I hope to continue the use of these cuts and gain experience as I go. Make sure the next time you’re walking the grounds of Winterthur, you’re on the look out for trees that have received coronet cuts.

I have included a few photos of coronet cuts. As time continues I hope to share some of my own photos!

-Kevin Braun, Winterthur Senior Arborist

The winter flowering display in the Winterthur garden is slow to unfurl. It usually begins in December with the first snowdrop emerging and when that occurs, it’s the equivalent of finding gold in what is the darkest and sometimes bleakest month of the year. Individual snowdrops emerge over January and February to form large, subtle sweeps of white, later punctuated by the yellow buttercup-like flowers of winter aconite. This color combination finally yields to the serenity of blue from glory-of-the-snow and Siberian squill that carpets the landscape throughout the garden. The accents of early flowering shrubs and trees of this time—witchhazel, wintersweet, fragrant honeysuckle and cornelian cherry dogwood—provide color but pale in comparison to the electric display of one of the stalwarts of the April garden, forsythia. I think in the winter months that our color-starved eyes watch in anticipation for any sign of life; like a child waiting to open presents.

The tranquility of the winter flowering garden disappears as April comes onto the scene with the subtlety of a wound up jack-in-the-box. Vibrant color abounds: purple of early rhododendron, pinks from cherries and magnolia, vivid yellows from forsythia and the warm-hued, rainbow assortment of colors from flowering quince. All of which are heightened by the addition of spring green from emerging leaves and awakening lawns. The gradual progression of winter flowers is exchanged for a riot of spring ephemerals, with flowers sometimes lasting but a few days; if you don’t catch them, they’re gone! An April garden is the equivalent of what many of us are experiencing right now, the pent up energy to get out!

I have made this confession before that I love winter and the winter garden. It’s quiet and reflective and I revel in the luxury of looking at the detail of the garden at that time. April is certainly not that but I strangely love and anticipate this month in its own way as it is just brimming with life, hope, anticipation and pure sensory overload—visual, olfactoral, and audible. It’s the “recess of months” in the garden!

Whether you are reading this blog from far away or if you are a regular visitor of the garden, you are watching spring roll past, perhaps missing some of your favorite sights. Below are snapshots of April thus far, some already passed and some from as recent as this week. Well, I have made you wade through my writing to get to the eye candy; enjoy the riotous colors of the season.

One of our notable color combinations, Korean rhododendron and winter hazel.

Happy bees amongst the flowers of Prunus ’Accolade’, flowering cherry.

Delicate cup flowers of saucer magnolia at Magnolia Bend.

The two harbingers of spring; forsythia and daffodils!

The assorted colors and shapes of Chaenomeles or flowering quince in the Pinetum.

Quince looking down toward the Sundial garden.

The Sundial Garden perfectly choreographed with quince, spirea,
and magnolias.

Sanguinaria canadensis or bloodroot; one of our fleeting natives.

Claytonia or spring beauty, another native, inundating the Conservatory Lawn.

Ipheon or starflower

Crabapples coming into flower with Ipheon carpet below.

Tulips—in our only deer-safe area of the garden!

Anemone apeninna, Italian windflower in Azalea Woods

Uvularia or bellwort with forsythia in the background.

Sessile trillium with anemone in Icewell Terrace.

Exochorda or pearlbush just on the verge of a flowery explosion. Buds are responsible for its common name.

“We need the tonic of wildness…We can never have enough of nature.” – Henry David Thoreau, Walden

I find enjoyment, inspiration, enlightenment as well as solace in nature.  It is a connection that is available for anyone to make.  In her book, The Curious Nature Guide, Clare Walker Leslie states, “Exploring nature knows no age limit, no skill requirement, no time limit, no location or destination.”  All one needs is to look out the window, stand in a doorway, or step outside.  I happened across her book, a few years ago, while looking for inspiration on keeping a nature journal. What I discovered, was a jewel of a book that I found myself turning the pages of over and over again.  With many people currently homebound, I thought it would be the perfect time to share this book with others, adults and children alike, as it provides a welcome resource on how to connect with nature at home.  A description of the book (accompanied with images), borrowed from an online retailer (Amazon), is as follows,

“With dozens of simple prompts and exercises, best-selling author, naturalist, and artist Clare Walker Leslie invites you to step outside for just a few minutes a day, reignite your sense of wonder about the natural world, and discover the peace and grounding that come from connecting with nature. Using stunning photography as well as the author’s own original illustrations, The Curious Nature Guide will inspire you to use all of your senses to notice the colors, sounds, smells, and textures of the trees, plants, animals, birds, insects, clouds, and other features that can be seen right outside your home, no matter where you live. Sketch or write about one exceptional nature image each day; learn to identify cloud types and the weather they bring; or create a record of what you see each day as you walk your dog. Easy, enjoyable, and enlightening, these simple exercises will transform your view of the world and your place within it.”










Whether you decide to get a copy of this book or not, take a moment to look outside your window…nature is there!

Many of our home gardens are getting a spring cleanup; raking leaves, cutting back perennials and putting down mulch. Working in the Winterthur garden has made me look differently about my approach to this yearly task.

Our early bulb displays necessitate a fall cleanup where we shred the fallen leaves and perennials in place to provide a mulch through which the bulbs can easily emerge. We utilize riding mowers in the larger areas and push mowers in tighter spots—-between shrubs—-to achieve this look. For the volume of leaves and the acreage that we cover, we have found this to be the best way to manage our “debris” in the garden.

I have applied this method of cleanup to my own home garden until I lost a few large trees and have since adapted a slightly different approach.

It used to be that I would mow the leaves on my lawn weekly in autumn and when they finished dropping, I would take the mower through my gardens and “put them to bed”. With fewer leaves, I have modified my tactics. Instead of weekly lawn/leaf mowing I blow the leaves into my beds. I also keep the leaves whole which allows for a more persistent mulch covering and also a better insulation for the roots from frost heave. Roots are not the only ones that appreciate this blanket; so do many insects. These in turn are a wonderful food resource for many of our overwintering and migratory birds (and my chickens like it too!)

Bantam chickens rooting through leaf debris for insects.

I initially leave the perennial stems intact to help keep the newly fallen leaves in place in the beds. As the winter wetness comes and the leaves naturally compact a bit, I will choose a warmer winter day in mid to late January (earlier this year) to take my string trimmer and, from top to bottom, shred the stems leaving them to add to the mulch layer in the beds.

No two stalks are alike and it’s interesting to see “what plants are made of”. Many perennials such as hosta, astilbe and grasses chop finely while stalks of Amsonia for example turn into a fibrous mass and thicker stalks of Joe-pye weed are best broken by hand or pruners. Some perennials are easier to chop earlier in the season and some later in the season when they are drier and easier to pulverize. Its another layer of experimentation and observation in the garden!

The leaves and fragmented stems are soon to be covered by emerging bulbs and perennial foliage. There is also an added benefit of leaving this debris behind; it provides nesting materials for the birds.

Daylilies emerging through leaves and shredded stems .

Depending on location, every garden is going to be a host for different birds. Mine happens to be a favorite of the common grackle. They root through the debris pickings and travel to my neighbor’s evergreens to make their nests. One of their favorites to gather is the fibrous shredded Amsonia stalks. I will gather these masses of tangled fibers and break them into finer pieces that are easier for the birds to use for nesting material.

Mass of shredded Amsonia stalk “fibers”.

Amsonia fibers teased into bird friendly sizes.

Not sure what birds you have in your garden or their favorite nesting material/sites? There are many wonderful field guides available and of course plenty of information on websites such as the Audubon Society. Personally, I like the portability of reference books.

Two staples on my bookshelf next to the binoculars.

This spring will likely see us spending more time at home and perhaps more time in our own garden or walking through natural spaces. What better time than now to feel some connectedness with how we care for our garden and the wildlife around us?