Sword Fern, Nephrolepis – Care and Propagation

Sword fern is considered to be extremely picky about its location. In direct sunlight, the leaves get brown spots and dry up, but if the planting place is too dark, the entire growth of the ornamental plant suffers. However, the Nephrolepis prefers a bright place with only a few hours of sunshine per day. Due to the lush and wide growth, it is sufficient if the plant is slightly elevated near an east or west-facing window. Also avoid being in close proximity to radiators. Under these conditions, the sword fern can develop optimally.

The substrate should have a high peat and humus content. Mix conventional potting soil with compost from the garden and add peat to a third. However, if the location and humidity are right, older plants can also cope with normal potting soil.

watering and fertilizing

The plant has a high moisture requirement, but at the same time is sensitive to waterlogging. Pour in lime-free water as soon as the top layer of soil has dried noticeably. When planting, a layer of potsherds should be laid out on the bottom of the planter. With this you ensure that excess water can drain faster from the roots of the sword fern. In addition to the normal water supply, the plant also needs high humidity. Spray the fern regularly with a water atomizer or use other means to ensure that the room humidity increases permanently. For example, you can choose a location near an aquarium or you can operate an indoor fountain in the same room.

Between March and October, the sword fern must be supplied with a fertilizer. Natural nutrient suppliers, such as compost or horn shavings, are rather unsuitable for indoor plants. Therefore, use a liquid or long-term fertilizer and use it strictly according to the package instructions. However, in the cold season the plant is dormant. If you add nutrients during this time, you quickly risk over-fertilizing. A yellowish discoloration of the fronds, for example, is not always due to a lack or excess of water. The fern also shows these signs when there is an excessive supply of nutrients.

multiply

To successfully propagate sword ferns, you should do root division or use stolons.

• Root Division – This involves severing the root ball of older and well-developed plants with a sharp ax or scissors. The fern should be divided into pieces of the same size, which you then plant directly in separate pots. Further care measures are not required.
• Stolons – Older plants develop small, scaly stolons directly from the rhizome. You can carefully separate these in the spring and plant them in a small container with humus-rich peat soil.
• Sowing – Another possibility of Nephrolepis propagation is spore sowing. However, this method is extremely time-consuming and only succeeds with pure sword fern species. In addition to patience, for spore reproduction you will need the following materials:
  • Paper
  • potting soil
  • lime-free, boiled water
  • perforated foil
  • shallow planter

Fern spores are found in dark capsules just below the fronds. Cut leaves with ripe capsules and put them on a piece of paper for a few days. In a warm environment, the capsules open within a few days and drop their powder-fine contents. Scatter the fine spores in the prepared planter and moisten the nutrient-poor substrate well with a water sprayer. High humidity is necessary for successful germination. Therefore, attach the transparent film over the flower pot and take it off for about half an hour every day. This will prevent unwanted mold growth. Periodically, the soil must be moistened again with lukewarm water.

In a bright, warm place, a moss-like covering forms on the ground within a few weeks. This is carefully transferred to a second planter with a knife or a spoon. Under ideal conditions, young sword ferns develop from this over a period of several weeks. In addition to high humidity and a warm room temperature, you should ensure that the substrate and the water are not contaminated with germs. Contaminating tools or unboiled water are often the reasons why the fern spores do not develop.

repot

As soon as the roots of the Nephrolepis completely fill the planter, the lush growing plant needs to be repotted. With older ferns, this is often only the case after three years; younger plants should be transplanted annually. It is perfectly sufficient if the new flower pot is only a few centimeters larger than the previously used container. Repot in the spring, before the main growing season of the plant begins. This ensures that the sword fern can acclimate well in the new substrate and that the fronds do not discolour. When repotting – and also when inserting newly purchased ferns – you should proceed as follows:

• Liberate the root ball generously from the old substrate.
• Create a drainage layer in the new planter.
• Half fill with a mixture of peat and soil.
• Use sword fern.
• Fill the remaining cavities with substrate and press firmly.
• Pour vigorously with lime-free water.

With this action, you can simultaneously divide the roots of larger plants to rejuvenate and propagate the fern. Because of the size, there is no need to place several of the Nephrolepis in the same flower pot.

To cut

Sword ferns only need to be pruned in some cases. Trim the fronds a few inches if they have dried out or discolored tips. You can also easily regulate the lush growth of the sword fern with one cut. This measure is often necessary, for example, when the fronds of the plant have already reached a circumference of more than 1 meter. To do this, carefully cut the roots of the fern and then put the plant back in the old planter.

hibernate

Nephrolepis, which originates from the tropics, is a pure indoor plant and should only be moved to sheltered places on the terrace or balcony in summer. Tropical plants also take a kind of vegetation break during the cold season and slow down their growth. The winter quarters must not fall below a room temperature of 10°C, at the same time the supply of fertilizer must be stopped. Avoid being in direct proximity to radiators and ensure high humidity in warm rooms. This will prevent the tips of the fronds from discolouring and at the same time protect the plant from infestation with spider mites.

Sword fern species bought in winter often cannot cope with the abrupt change between air-conditioned sales rooms and their own heated interiors. Avoid buying new plants during this period. Because despite an increase in humidity and other care measures, the plants need a lot of care and time to recover.

diseases and pests

Dried up and discolored fern fronds are often due to care errors. Fungal pathogens are rarely found on the sword fern, but the plant provides a nutritious basis for some harmful insects.

• Spider mites: These pests attack indoor plants, especially in winter when the room air is dry. The pests, which are only a few millimeters in size, use their mouthparts to extract the cell sap from the plants. Left untreated, spider mites first cause massive discoloration of the leaves, which then dry up and die. The use of natural predators, such as assassin bugs or lacewing larvae, is rarely feasible in the living room at home.

However, increasing the humidity is just as efficient as the animal helpers: quarantine the affected plant and spray the fern generously with lime-free water. Then wrap the plant and the flower pot completely with a transparent film. If necessary, repeat this measure over several days to completely remove all arachnids. In order to counteract an infestation in general, direct proximity to radiators should be avoided and high humidity in the room should be ensured.

• Aphids: – Like spider mites, aphids also feed on the cell sap of the plants. The lice prefer to sit on the underside of the fronds, where they are often only discovered due to the superficial discoloration of the leaves. The honeydew, the excretion of the insects, also creates a sticky coating on the heavily infested parts of the plant. To rid indoor plants of aphids, you should shower the fern with a strong jet of water and lather it with soapy water. You can also spray indoors with a decoction of field horsetail or nettles. You should only use insecticides if natural home remedies have been ineffective in controlling them.
• Root rot: Sword fern is an extremely moisture-loving plant, but is extremely sensitive to waterlogging. If an unpleasant odor penetrates from the soil and the fern is visibly taking care of itself, these symptoms inevitably point to root rot. There is no effective chemical remedy for this disease. Transplant the fern into a dry substrate without removing the rotting roots. If the infestation is not very advanced, the plant often regenerates itself.

sorts

Of sword ferns, the two species “Nephrolepis cordifolja” and “Nephrolepis exalta” have proven to be popular houseplants. Both species are available in different growth forms and sizes.

Nephrolepis exalta: Depending on the variety, the size of the feathered fern fronds varies between 80 and 180 centimetres. Young leaves of this sword fern variety often tend to develop fronds without feathering. Cut them back heavily to regain normal growth.

Nephrolepis cordifolja: The coloring of these varieties varies from light to dark green, but the fronds of the plants are seldom as distinctive in feathering as those of other sword fern species.