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What are epiphytic ferns?

Many of the tropical ferns sold as houseplants are ‘epiphytic’. This simply means they naturally grow on other plants rather than in the ground (in a similar way to many tropical orchids). In their native

A native plant is one that originated or arrived naturally in a particular place without human involvement. In the British Isles, native plants are those that were here during the last ice age or have arrived unaided since.

forests, they take root on tree branches or in crevices in bark

Bark is the outermost layer of woody plants (trees, shrubs and woody climbers). It is several cells thick and provides protection against physical damage, disease and environmental stresses. Bark comes in a wide variety of colours and patterns, and these can help gardeners when identifying plants. The fissures and crevices of bark on older plants also creates valuable habitat for many garden creatures as well as lichens and small plants.

, and get all their moisture and nutrients

To grow well, plants need a wide range of nutrients in various amounts, depending on the individual plant and its stage of growth. The three key nutrients usually taken up from the soil are nitrogen, phosphorus and potassium. Plants also need carbon, oxygen and hydrogen to make carbohydrates — their main energy source. Carbon and oxygen come from the air as carbon dioxide, while hydrogen is drawn from water absorbed by the roots. Other important soil nutrients include magnesium, calcium and sulphur. Most garden soils contain enough of these nutrients to support healthy plant growth.

from rainfall, humid air and accumulated debris. Perched well above the forest floor, they get more light, but less access to moisture.

When grown as houseplants, tropical epiphytic ferns are best planted in pots of free-draining compost

Can refer to either home-made garden compost or seed/potting compost:

• Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

. Several species will produce thick furry roots (or rhizomes

Rhizomes are creeping swollen root-like structures that are actually adapted stems. Roots, stems with leaves and flowers are produced along its length. See plants such as Anemone nemorosa, bamboo, canna, border iris.

) on the compost surface that will grow down the outside of the container, like they would over a tree branch in the wild.

As these ferns have adapted to limited moisture, they can easily be damaged by overwatering, although they do like high humidity

The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting.

. This can make them a little tricky to grow well, but if you can provide the conditions they need, they’ll reward you with lush ferny fronds that will bring a tropical vibe to your living space.

Choosing epiphytic ferns

The most widely available epiphytic houseplant ferns – and the most suitable for growing in our homes – are:

• Asplenium nidus – the bird’s nest fern, one of the most popular and easy to grow, with a clump of long, strap-shaped fronds that unfurl to form a shuttlecock shape
• Davallia canariensis – one of several known as hare’s foot ferns, due to the thick furry roots that emerge from the pot; they also have delicate feathery fronds
• Nephrolepis exaltata– the sword fern, with long feathery fronds; and the ever-popular Boston fern (N. exaltata ‘B´Ç²õ³Ù´Ç²Ô¾±±ð²Ô²õ¾±²õ’) with its fountain of arching, serrated foliage
• Phlebodium aureum– a hare’s foot fern with typically thick furry roots, along with slender-stemmed, glaucous foliage
• Platycerium bifurcatum– the stag’s horn fern is a real show-stopper, due to its impressive, branching, antler-like fronds

All of the above have an RHS Award of Garden Merit, having been trialled by RHS experts and found to be reliably good performers.

Choosing the best houseplants

Houseplants: to support human health

Buying epiphytic ferns

These tropical ferns are readily available from houseplant retailers, especially the ever-popular and . Larger retailers offer the widest choice.

When buying, choose plants with lush, unblemished foliage and healthy roots that aren’t overcrowded in the pot. If there are large furry roots on the compost surface, this is their natural way of growing and nothing to worry about – it just adds to their character!

Buying: garden centre plants

Buying: mail order plants

Newly bought ferns can be kept in their pot for several years. Once the roots become densely crowded or start appearing through the drainage holes, repot in spring into a container that’s just slightly larger than the rootball

The roots and accompanying soil when a plant is removed from a container or lifted from the ground.

. Avoid using a much larger container (overpotting), as this may lead to root rot.

Epiphytic ferns like an open, moisture-retentive but well-drained ericaceous (acidic) compost

Can refer to either home-made garden compost or seed/potting compost:

• Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

. An ideal mix would be two parts peat-free ericaceous

Plants that thrive in acid or ericaceous soil, which has a pH of less than 7 (neutral). You can measure your soil pH using a simple testing kit. Ericaceous or acid-loving plants include rhododendrons, camellias, heathers and blueberries.

compost, one part perlite

Perlite is a naturally occurring volcanic rock which, when heated to high temperatures, expands to produce lightweight, micro-porous granules. It was traditionally added to compost to aid drainage and aeration, however, its manufacture, packaging and distribution has a big environmental impact, so locally-sourced grit or gravel is now preferred.

and one part medium-sized orchid bark

Bark is the outermost layer of woody plants (trees, shrubs and woody climbers). It is several cells thick and provides protection against physical damage, disease and environmental stresses. Bark comes in a wide variety of colours and patterns, and these can help gardeners when identifying plants. The fissures and crevices of bark on older plants also creates valuable habitat for many garden creatures as well as lichens and small plants.

. Alternatively, many of these ferns will be happy purely in orchid compost.

Some epiphytic ferns produce thick furry roots ( rhizomes

Rhizomes are creeping swollen root-like structures that are actually adapted stems. Roots, stems with leaves and flowers are produced along its length. See plants such as Anemone nemorosa, bamboo, canna, border iris.

) on the compost surface (especially hare’s foot ferns such as Davallia canariensis and Phlebodium aureum). This isn’t a sign they need repotting, it’s just their natural growth habit. But when it is time to repot them, take care not to bury these surface roots.

Continue repotting every few years, once the roots fill their container.

See our guides on repotting houseplants:

How to repot a plant

Peat-free compost choices

Young ferns can also be planted in a glass terrarium, or in a kokedama (a traditional Japanese way of planting in a moss ball, which can be hung up) – watch our video guide to find out how:

Location

Bright, indirect light is best, such as in a west- or east-facing window. To grow these ferns in a south-facing room, position them behind sheer curtains or away from the window.

A bright bathroom is an ideal location for them, where they can also enjoy the higher humidity

The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting.

.

Temperature

Epiphytic ferns grow well in temperatures between 16°C (60°F) and 30°C (85°F). Keep them out of cold draughts and away from hot radiators.

Humidity

These tropical ferns like humid air, so place the pot in a saucer over a tray of damp gravel, or group several plants together, which will moisten the air around them. Mist the leaves regularly too.

Browning of the leaves may indicate the air is too dry, especially in winter when the heating is on. A steamy bathroom is often the best home for these humidity-lovers.

Many ferns can also be grown in a glass terrarium, where the air is kept humid.

For more on increasing air humidity, see our video guide:

Watering

Only water once the compost

Can refer to either home-made garden compost or seed/potting compost:

• Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

starts to feel dry. Despite their lush, leafy appearance, these tree-dwelling ferns are adapted to having less access to water than most typical ground-dwelling ferns, so avoid the temptation to water them too much – you may inadvertently end up killing them with kindness.

If the leaves turn brown, don’t just assume they need more water – it's often a sign they need less, so always check the compost first. When watered too often or left sitting in water for too long, the roots are likely to rot.

If possible, water with rainwater or filtered water. This helps to maintain the acidity of the compost. Hard (alkaline) tap water, if used too often, can neutralise the acidic ( ericaceous

Plants that thrive in acid or ericaceous soil, which has a pH of less than 7 (neutral). You can measure your soil pH using a simple testing kit. Ericaceous or acid-loving plants include rhododendrons, camellias, heathers and blueberries.

) conditions these ferns like. Avoid giving them very cold water – let it sit for a while until it reaches room temperature first.

Collecting, storing and reusing water

Houseplants: holiday care

Feeding

To boost growth, you can feed epiphytic ferns with weak orchid fertiliser from April to October.

Fertilisers

No pruning or training is required, other than removing any dead or browning leaves to keep the plant looking its best.

There are several ways to grow new plants, depending on the type of fern:

• Ferns with creeping rhizomes
  

  Rhizomes are creeping swollen root-like structures that are actually adapted stems. Roots, stems with leaves and flowers are produced along its length. See plants such as Anemone nemorosa, bamboo, canna, border iris.

  , such as Davallia and Phlebodium, can be easily propagated by division
• Clump-forming ferns can simply be pulled apart into smaller clumps, each with plenty of leaves and roots. If the rootball
  

  The roots and accompanying soil when a plant is removed from a container or lifted from the ground.

  is tightly packed, you may need to cut it with secateurs
• Many ferns can also be propagated from spores, but this can be a challenge

To keep these tropical ferns thriving, it’s important to give them the conditions they need – warmth, humidity

The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting.

, bright indirect light and moderate water. Too much or too little of any of these can cause problems and, if not corrected, the plant may decline and eventually die. So take action if you notice:

• Leaves turning brown – may be a sign of too much water, watering with hard (alkaline) tap water instead of rainwater, sun scorch from too much direct light, low humidity, a cold draught or being too close to a heat source such as a radiator. Also see our video guide to light levels and our video guide to houseplant watering
• Mottled leaves or poor growth – may be caused by sap
  

  Sap is a fluid that circulates through a plant's vascular system, in a similar way to blood moving through our veins. Phloem sap carries the sugars produced in the leaves by photosynthesis down to roots and other storage organs, as well as carrying minerals and hormones. Xylem sap is watery and transports nutrients absorbed by the roots upwards to the rest of the plant. Some plants leak sap from wounds or pruning cuts, and this is known as bleeding.

  -sucking insects, including red spider mites and mealybugs

How to help a poorly houseplant

Leaf damage on houseplants