Fanning ferns reveal their beauty
Luxuriant ferns bring a fresh green canopy to the garden as they slowly unwind
agently unfurling fern frond slowly performs one of nature’s miracles of transformation. Gradually, it turns from a hairy stem, shaped like a shepherd’s crook, to a majestic, feathered wand of foliage. Amid the brightly coloured show of spring-flowering bulbs, the intricacy of a developing fern is complex and captivating. The coiled young fern fronds, known as crosiers, demand to be seen every day as they gradually uncurl into a myriad of shapes. Many hardy ferns are suitable for growing in British gardens. Whether evergreen or deciduous, low-growing or planted for height and stature, they bring an ethereal beauty. Some grow best in the sun; others prefer cool, shady spots. They are not restricted to the ground. Some, known as epiphytic ferns, are capable of growing in the crevices of trees and rocks. They have one thing in common: once unfurled, they provide an abundance of decorative greenery.
Their shapes and varied shades of green make ferns attractive garden plants. None produce flowers, instead most multiply through spores. These come from rust-coloured capsules, called sori, found under the fronds. The frond is the whole leaf stalk, including the individual leaves, which are known as pinnae.
Ideal conditions
Many hardy ferns are indigenous, found in abundance in British woodland. These are the easiest to grow. “Native ferns are more adaptable than non-natives,” says Steven Fletcher. He runs the fern nursery, Fernatix, in Suffolk with his partner Kerry Robinson. Steven started growing ferns in 1995, using them to decorate floral displays of orchids at flower shows for the Cambridge Orchid Society. Now, however, he specialises in showing and growing ferns alone. “Hardy ferns are very forgiving plants,” he explains. “British natives will grow very well in moist situations, but they will also tolerate dry conditions because they have to in the wild. There, they must compete with other plants, and the tree canopy is like an umbrella in the summer. As a rule, if a fern starts dry, it will do dry. “Part-shade is the best aspect for most ferns,” he says. “They will grow in full sun, but they turn yellow around July and start to look terrible from then onwards.” Planted in the right place in the garden, they do not need any extra care. A neutral to alkaline soil suits the majority of hardy ferns.
“Only spread a fern-frond over a man’s head and worldly cares are cast out, and freedom and beauty and peace come in.” John Muir, ‘My First Summer in the Sierra’
In Steven’s view, native ferns from the genus Dryopteris are the most straightforward to grow. Stately fan-shaped plants, with wide fronds, they bring architectural value to the garden. The majority are evergreen or semi-evergreen, holding their leaves if the colder months are not too harsh. “Dryopteris grow well in shade,” says Steven. “Some of them, such as Dryopteris affinis ‘Cristata’, can stay evergreen in a mild winter.” These ferns grow well in dry shade, unlocking the opportunity to create a full, lush green scene in what could be difficult growing conditions. Particular ones he singles out as being very attractive garden plants include Dryopteris dilatata ‘Crispa Whiteside’. This is a frillier-edged version, growing to 2ft (60cm) in height. It makes a fine plant for decorating a border or container edges. A taller contrast comes from Dryopteris filix-mas ‘Linearis Polydactyla’. This produces very slim, frothy-looking fronds up to 4ft (1.2m) tall. “This fern is completely different from most Dryopteris,” says Steven. “It works well when grown in a collection of different ferns because of its individuality.”
Resilient natives
Another group of easily recognisable native British ferns, are the polystichums. The most familiar is Polystichum setiferum, the soft shield fern. This sends out sprays of wide, soft fronds reaching up to 4ft (1.2m) in height, creating a shuttlecock shape. Thriving in damp soils, these ferns become more resilient with age. “Polystichum will also take dry conditions once they are established,” says Steven. “There are many hundreds of variations, although you would need an eyeglass to distinguish between lots of them.” Some forms have outstanding points of difference, however. Polystichum polyblepharum is a compact plant that has beautifully proportioned, noticeably shiny fronds. It grows to approximately 2ft (60cm). Polystichum setiferum ‘Herrenhausen’,
or soft shield fern, is notable for having darker green fronds. Although ferns do not flower, one of them, Osmunda regalis, is sometimes called the flowering fern. This is because the distinctive orangey-brown fronds, which emerge in summer and bear the spores, look like flower stalks. Osmunda regalis is also known as the Royal fern for its stately appearance, reaching up to 8ft (2.5m) in height. Deciduous, as it ages, the whole plant turns a rich reddish-brown in autumn. The elegant new growth of most fern fronds appears in all its splendour in late spring. One which emerges later in the year is Polypodium. “These have a tendency to produce new growth very late in the growing season, sometimes not appearing above ground until July or August,” says Steven. “They can still look good through the winter, when the leaves appear fresh.” Polypodiums are short rhizomatous ferns, which spread through underground stems. Reaching between 15-30cm tall, they are well suited to being grown as a ground cover plant. Their late appearance makes them useful for providing fresh foliage to shady areas when spring’s growth is starting to dull. Approximately the same size, but with a very different habitat, is the maidenhair spleenwort, Asplenium trichomanes. This is an epiphytic fern which finds its home in nooks and crannies, or even in a tree stump which it will creep over. It can spore around if grown in a constantly damp, shady area, such as a north-facing stone wall. It can also work well in hanging baskets. Another epiphytic British native fern is Polypodium vulgare, an evergreen with thick pinnae, which has been known to grow in the crevices of old trees.
Asian beauties
British native ferns are the easiest and most reliable of the hardy ferns to grow. However, in Steven’s opinion, the most beautiful is one from East Asia. “The Japanese painted ferns, athyriums, are the nicest looking,” he says.
The most commonly grown is Athyrium niponicum var. pictum, which has ghostly, silvery leaves. Plants with silver leaves are often drought-tolerant, reflecting bright sunlight. However, athyriums will not survive drought and need to be grown in very damp soil. “They are very decorative, and the foliage is a gorgeous apple green in spring,” says Steven. “They are generally deciduous, dying down to a crown in winter, or there may not even be evidence of a crown at all.” Marking the area where it dies down with bamboo canes helps prevent it being disturbed by accident before it reappears the following spring. Equally as delicate-looking but otherwise quite different in appearance, is Athyrium filix-femina ‘Frizelliae’. This fern needs the same damp conditions to display its thin and lacy fronds, which fan out to resemble a grass-green firework display. Also from Asia, but closely related to Polystichum, are Cyrtomium ferns. One of the most eye-catching is Cyrtomium macrophyllum, best grown in full shade. This is known as the large-leaved holly fern because of its extraordinary fronds. These display very large, wide pinnae, not dissimilar to holly leaves, though without the prickles. It looks more like a shrub than a fern at first glance and grows to 2ft (60cm) tall and wide. Another distinctive, hardy Asian native is Onoclea sensibilis, the sensitive fern. Its fronds have rounded edges, strangely reminiscent of oak leaves. “This fern must be grown in neutral to acid soil, but it is a lovely plant once it gets going,” says Steven. It also serves a useful purpose in the garden as a temperature indicator, which also explains the ‘sensitive’ part of its name. “The first frost of the season will completely knock it down,” he adds. The gardener knows that when the foliage suddenly dies off, winter is on its way. But there is no need to worry. The wonder of an unfurling spring fern will soon reappear.
“...Who hath not made A minutes waste of time and sat him down Upon a pleasant swell to gaze awhile On crowding ferns bluebells and hazel leaves” John Clare, ‘Wood Rides’