FERN Collection at OpdeHaar gardens 

On this page about the fern collection at OpdeHaar there is information on and photo’s of:

Fern garden at opdeHAar
Fern garden at OpdeHaar


Fern collection built up over 30 years

We have an extensive fern collection at OpdeHaar. Ferns are generally associated with moist, shady places and are indeed ideal plants for a woodland garden. Our fern collection is scattered throughout the woodland garden but in 2020 we established a stumpery which now houses a large number of our ferns in one area.

Ferns were the first plants to establish themselves on land around 350 million years ago. However, the earliest species which we would still recognize today appeared about 160 million years ago.

All the photos were taken in our garden. Click on the photos for a larger image and a slideshow

Native ferns in our fern collection

It is immediately apparent to any visitor that our gardens provide an ideal habitat for a variety of ferns. However, when we first cleared away all the brambles from the woodland area, there was basically only Dryopteris dilatata (Broad Buckler fern). – the most commonly occurring fern in the Netherlands  In fact, Broad Buckler fern Dryopteris dilatata almost reaches weed status in our woodland as its spores germinate freely. The royal fern (Osmunda regalis) is our largest native fern and several clumps also existed when we came here and they continue to appear spontaneously throughout the woods.

We also found a clump of Polypodium vulgare just outside a boundary fence and an isolated Blechnum spicant on the edge of a ditch.

For the first 30 years of developing the garden we established our fern collection and  planted our ferns in many locations around the gardens. Most of the ferns which we have planted, apart from the common Male fern and the more delicate Lady fern (Athyrium filix-femina), are labelled. The Lady fern is spreading notably along the banks of the ditch that separates our property from that of the Geldersch Landschap on the western boundary of the wood. It is readily identifiable by its lighter green and more finely structure fronds.








In the final months of 2019 we had to fell a massive Abies grandis conifer which was dying and decided to use the massive sections of trunk to construct a stumpery fern garden in an adjacent section of the woodland. The stumpery is described here.

We then planted the stumpery with a large variety of ferns, adding to our already extensive fern collection.

Many varieties of ferns

Appreciating ferns requires a bit of patience and ideally a hand lens is useful to see all the intricacies of frond structure etc. Until the construction of the stumpery, this required finding the various ferns scattered around the garden although I had sometimes located Polystichum setiferum cultivars near to each other. People who want colour (apart from green) as a predominant part of their displays tend not to think of ferns. However, selections of Athyrium nipponicum introduce this feature into the world of ferns. We are establishing a collection of athyriums in the stumpery

For more information about ferns see: Hardy Fern Library


There are about  700 species of ferns in the genus asplenium. The most common vernacular name is spleenworts, applied to the more “typical” species.  It is the largest (and some people think) it is the only species of the spleenwort family. There are very small varieties and also very large varieties with plain fronds growing from a rhizome. Tropical forms and small wall-ferns or rock-ferns, growing in cold and temperate climates also occur.

Their common feature is the lines of sori or spore clusters on the underside of the leaves, lying sideways on to the side veins. The name “spleenwort” derives from an old believe that the ferns were useful for curing ailments of the spleen










Athyrium filix-femina – spore clusters on the underside of the fronds

The lady-fern,  Athyrium, is a genus of about 180 species of ferns with a wide distribution. It is placed in the family Athyriaceae, in the order Polypodiales.  The common name “lady fern” refers in particular to the common lady fern, Athyrium filix-femina. This is a large, feathery fern native throughout most of the temperate Northern Hemisphere.  In The Netherlands it is often abundant (one of the more common ferns) in damp, shady woodland environments and is also grown for decoration.

Its common names are “lady fern” and “female fern”. These names refer to how its reproductive structures (sori) are concealed in an inconspicuous – deemed “female” – manner on the frond.  Alternatively, it is said to be feminine because of its elegant and graceful appearance.

Most Athyriums die back in winter. They have a short, creeping, upright rhizome. A few tropical varieties, such as Athyrium oosorum, are tree ferns which can grow to several meters in height.

The fertile and sterile fronds are lancet or elliptical shaped, usually light green, 20-30cm long and 5 – 25 cm broad. Sori, clusters of spores, appear as dots on the underside of the frond, 1–6 per pinnule or subleaflet. They are covered by a prominently whitish to brown kidney-shaped indusium. Fronds are very dissected, being 3-pinnate. The stipe may bear long, pale brown, papery scales at the base.

Photos of athyriums









The hard fern or deer fern,  Blechnum,  is a genus of 150–220 species of ferns with a global distribution. Most of the species occur in tropical regions of the Southern Hemisphere. However there are a few species which grow in cool temperate climates such as B. penna-marina, which occurs around Cape Horn in Chile. While B. spicant which grows in colder climates is found as far north as Iceland and northern Norway.

A fairly tender lovely specimen in our garden is Blechnum tabulare. It started life as far as I am concerned as a matchbox-sized plant which was clearly trodden upon in the famous Derreen woodland garden in the south of Ireland. As it looked interesting  I retrieved out of the path and replanted it back home to add to our fern collection.


Most blechnums are herbaceous plants, but a few species (e.g. B. buchtienii and B. schomburgkii in Ecuador) are tree ferns with stems up to 3 m tall.

The characteristic of the Blechnum species is that it has both fertile and sterile fronds on the same plant. This feature distinguishes it from most other varieties.








Blechnum spicant is an evergreen fern which is very common in moist woods and in poor soil. Fertile fronds are about 70cm long, bear the spores in a line parallel to the central vein, have small sub-fronds and stand upright. The spores ripen in July and August. Sterile fronds are about 40cm long and flop onto the ground. 

Photos of blechnums










Dryopteris sporen
Dryopteris filix -mas spore clusters

The Dryopteris fern is commonly called wood fern or male fern (referring in particular to Dryopteris filix-mas) or buckler fern. It is a genus of about 250 species of ferns with a distribution in the temperate Northern Hemisphere. The highest species diversity is in eastern Asia.  They grow in woodland, open areas and sometimes on rocky ground in mountain areas. In The Netherlands 7-8 varieties occur naturally of which the Dryopteris dilata is the most common. Several of the species have fat and slowly creeping roots. The fronds form a vase-like ring. All the sori are round, with a kidney-shaped indusium. The stipes (stalks below the fronds) have prominent scales. In our wood Dryopteris dilata is the most common naturally occurring fern. 

Hybridisation is a well-known phenomenon within this group, and many species are formed by this method. The genus is also subdivided into Arachnoides, Crytomuim and Polystichum.

Photos of dryopteris










One of the fern genus in the Dryopteris family (wood ferns) is the Arachniodes. A number of species in this genus are known as “holly ferns”. There are between 100 and 140 species in the Arachnoides family. They occur mostly in tropical and sub-tropical areas, particularly in China and East Asia. It has symmetrical, small and triangular or 5-sided leaves and divided into 2 or 4. Fronds end in a point and have a papery or leathery feel. The stalk is about the same length as the frond and has more than 3 veins in a curve.

Carl Ludwig van Blume first described the genus Arachniodes  in 1828. At that time there was a  single Indonesian species Arachniodes aspidioides known.   However in 1961 Mary Douglas Tindale transferred the two species Byrsopteris amabilis and Byrsopteris aristata into the genus.

Photos of arachniodes










The genus Crytomium has about 15-55 species of ferns in the Dropteris family.  It is native to Asia, Africa (including Madagascar), and the Pacific Ocean islands (Hawaii). However in Belgium and The Netherlands Crytomium falcatum, commonly known as the holly fern, has been found in the wild. The species is very closely related to the genus Polystichum. Indeed recent research has suggested that it should be included within this category.

It grows in crevices, on coastal cliffs, streambanks, rocky slopes, and other moist, areas. This fern is a perennial plant with a large light brown rhizome.

Cyrtomium falcatum has leaves longer than 0.5m and made up of six to ten pairs of shiny bright green leaflets. Each leathery leaflet has a flat to wavy to slightly toothed margin and a netlike pattern of veining. The underside of each leaflet has sori beneath brown or black indusia.

Cyrtomium falcatum is a popular ornamental plant in temperate climate gardens (zones 7 to 10). It is hardier than most ferns. Light shade to deep shade is its preferred habitat. It is easily and quickly propagated by spores, but can be propagated via rhizome division.

Photos of crytomium










There are about 260 species of ferns in the genus Polystichum with a wide distribution. About 120 species are found in China alone, while nearly 100 species are found between Mexico and Brazil. North America has only 15 native species and Europe just 5 species. In the Netherlands there are 3 naturally occurring species: Polystichum aculeatum, Polystichum lonchitis and Polystichum setiferum. All are in our fern collection. Polystichum species like rocky areas in warm-temperate and mountainous tropical regions.

Polystichum munitum – The spore clusters are in two rows and the leaflets are arranged asymmetrically.

Many ferns of this genus have stout, slowly creeping rootstocks. They form a crown, with a vase-like ring of evergreen fronds 30 to 200cm long. The sori are round, with a circular indusium and the stipes  or stalks have prominent scales. Polystichum differ from the closely related fern Dryopteris genus. It has circular indusium in contrast to kidney-shaped. In addition the leaf blades have asymmetrical segments—one side is much longer than the other at the base. It has stiffer and rougher leaves than Dryopteris. The sori are in one or more rows on the underside of the leaf. Polystichums frequently hybridise in areas where 2 sorts overlap. 

Photos of polystichum









Matteuccia struthiopteris

The ostrich fern, Matteuccia struthiopteris (other common names are fiddlehead ferns or shuttlecock fern) is a crown-forming, colony-forming fern. It occurs in temperate regions of the Northern Hemisphere in central and northern Europe, northern Asia, and northern North America. The species epithet struthiopteris comes from Ancient Greek words, struthio meaning ostrich and pterion meaning wing.









Matteuccia struthiopteris grows from a completely vertical crown, particularly on riverbanks and sandbars. Lateral stolons (runners) are produced to form new crowns. Dense colonies are therefore formed which are resistant to destruction by floodwaters.

The fronds are dimorphic, with  almost vertical, 100–170 cm (39–67 in) tall deciduous green sterile fronds .They are usually 20–35 cm (7.9–13.8 in) broad, long-tapering to the base but short-tapering to the tip. The fronds do indeed resemble ostrich plumes, hence the name. Fertile fronds are shorter, (40–60 cm), brown when ripe, with highly modified constricted leaf tissue curled over the sporangia. They develop in autumn, persist erect over the winter and release the spores in early spring.

The ostrich fern is a popular ornamental plant in gardens. It has gained the Royal Horticultural Society’s Award of Garden Merit. When choosing a place of planting it should be taken into account that these ferns are very expansive.  In addition, its leaves often lose their beauty throughout the summer, especially if not protected from wind and hail.


A genus  of primarily temperate-zone  ferns is Osmunda of the Osmundaceae family. Five to ten species have been listed for this genus.

The species have completely dimorphic fronds or pinnae (hemidimorphic). Sterile fronds are large (0.3 to 2 m long) green and photosynthetic. The non-photosynthetic spore-bearing fertile pinnae have large, naked sporangia. In July and August the spores ripen uniformly at the same time. They have a showy golden colour so that the ferns look as if they are in flower. For this reason the genus is sometimes called the “flowering ferns”.   The plants can live for up to 100 years.








The genus is known in the fossil record back to the Triassic period from fragmentary foliage nearly identical to the living  Osmunda claytoniana. Paleontological evidence indicates that Osmunda claytoniana, a reputed “living fossil,” has maintained evolutionary stasis for at least 180 million years.

Osmunda regalis (Royal fern) occurs naturally in moist deciduous woods and on the sides of ditches. In other areas it is is quite rare. It is native to our garden and seeds itself profusely along the sides of the ditches. It is the largest native fern in the Netherlands and was protected, as it is relatively rare. However since 1st January 2017 the protection has been removed. We have also planted Osmunda regalis purpurescens which has purple juvenile stems, as a variant of this species.

Photos of osmunda








Tender ferns

When only two people are looking after a large garden, every plant which is put into a pot represents a small but collectively extra burden in terms of the daily attention required etc. Accordingly, we don’t have hanging baskets and you won’t find many annuals in our borders. However, pots of plants, which need greenhouse protection in winter, are distributed around the garden and these include some spectacular but tender ferns. 


One of these tender ferns is Dicksonia antartica, a tree fern. These are frost tolerant but they do need special protection to avoid rotting in the crowns in the winter months. We find that  it is easiest to put them under cover.


 I found Woodwardia unigemmata as a tiny plant in Spinner’s Garden near Bournemouth (UK) in 2003. It comes from the Himalayas originally. Both the Blechnum tabulare, mentioned earlier and woodwardia are candidates for planting in a protected position in the woods with winter protection.








Additional Information

I am more than aware that this brief summary hardly does justice to the ferns and we will expand it in the future as we expand our fern collection. 

See Hardy Fern Library for more information.   Martin Rickard. a fern specialist is present in the form of two books:

  • “The Plant finders Guide to Garden Ferns”, Timber Press, ISBN )-88192-567-5 “Gardening with ferns” David and Charles, ISBN 07153 1730X

Finally just a note to say that we do not get any commission for this hero worship either!

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