Family: Nephrolepidaceae
Common name: Asian swordfern, Rough swordfern
Asian swordfern is a lush green, perennial fern that is a very popular ornamental plant for indoor and outdoor gardens. They are native to Southeast Asia, but has been introduced to many more countries in tropical and subtropical regions.
Plant Characteristics
Asian swordferns grow in tufts or clumps of 15-20 long arching fronds growing from rhizomatous roots, which are thick brown cylindrical structures that grow horizontally along the ground. They also produce shallow fibrous roots that absorb water and nutrition from the atmosphere.
Like most ferns, these plants do not have typical stems; the rhizomes function is fleshy stems that store and conduct water and nutrients.
Leaves of the Asian swordfern are long, graceful fronds that arch outwards from the center. They are pinnate, which means that the leaves are divided into 20-50 pairs of small leaflets that grow outwards from the central stalk or rachis.
The leaflets have finely serrated edges, giving the plant a feathery and delicate look. Asian swordfern leaves are dark green with a glossy texture, and about 45-90 cm in length. The long arching leaves that grow in thick clumps can give your garden an elegant, lush, tropical vibe.
Asian swordferns do not produce flowers, fruits, or seeds, as is typical of most ferns. They reproduce through spores that are contained in specialized structures called sporangia, seen on the lower surface of the leaves.
If you turn over a mature leaf, you can see many circular brown spots along the edges of the leaves which contain the spores.
When the leaves mature and dry, they release the spores into the air. When the spores fall on suitable substrates, they produce new plants. This method of reproducton helps them to grow quickly and also to spread to new areas, making them invasive in some parts of the world.
Gardening Tips
Asian swordferns are excellent for growing indoors or outdoors, in flowerbeds, pots, or hanging baskets. In their natural habitat, these plants can grow as epiphytes on tree logs, rotting wood, rocky surfaces, or underneath large shade trees.
They prefer indirect filtered sunlight as bright, harsh sunlight can damage the leaves. These ferns need high levels of humidity. So they should be watered regularly and preferably misted during hot summer months.
It is also good to place the pots of ferns in a tray filled with water so that they can absorb the required moisture.
Asian swordferns can be grown near waterbodies like koi ponds where they bring an elegant tropical look to the garden, while also adorning the walls of the pond. When growing them in flowerbeds or pots, ensure that the soil is loose and well-draining, since the plants cannot stand overwatering or waterlogging.
Fertilization can be done once a month and stopped completely in the winter with the plant is dormant. Prune the fronds to remove any diseased or leggy ones.
These ferns are very closely related to Nephrolepis cordifolia or Fishbone fern, Nephrolepis exaltata or Boston fern, and Nephrolepis falcata or Fishtail sword fern.
Uses of Asian Swordfern
Asian swordferns are grown as ornamental plants in home gardens and landscaped areas, in flowerbeds, pots, or hanging baskets. They look beautiful in hanging baskets with their long leaves falling outwards over the edge of the container.
These plants make excellent ground cover in slopy areas where there is a risk of losing the topsoil to erosion.
They are also considered as excellent air purifiers that remove toxins like formaldehyde from the air. Hence they are good for indoor spaces like offices or malls where these plants can be placed near sunny windows. They cannot be grown in complete shade.
But these plants are considered invasive in some parts of the world due to their fast-growing and spreading nature. Asian swordferns can quickly cover large areas and also invade new territories with spores that germinate where they fall.
They are relatively easy to remove since the roots are shallow and not very strong to pull out manually. Any small piece of rhizome left behind can produce a new plant. So make sure the soil is raked and all pieces of rhizomes are removed, if you want to get rid of this plant.
Propagation
Propagation is through spores and root division.
Spores that are seen underneath the leaves can be collected by shaking dry leaves in a paper bag, or by ruffling them over a piece of paper. The dark brown spores that are collected can then be sown in moist, well-draining soil or cocopeat to germinate.
When the plant become too big for a pot, they need to be repotted. The roots can be gently separated or even cut with a sharp knife at this time, to produce separate plants.
Photographed at: Lunuganga, Sri Lanka
