Bird's nest ferns (Asplenium nidus) are naturally epiphytic, meaning they grow on the surface of other plants. In their rainforest homes, they can be found growing high in the crooks of trees. The common name derives from its large, nest-shaped rosette of light-green, slightly leathery radiating fronds and its ability to grow on trees due to is shallow root system.
Light
Indoors, an east- or north-facing window is ideal. Bird’s nest ferns grow well in filtered sunlight to a moderate amount of shade. Don’t expose them to direct sunlight other than the very early morning sun. Direct sunlight can burn the leaves.
Temperature and Humidity
Indoors, be sure to protect your plant from cool drafts, such as air blowing from an air-conditioning vent. The bird’s nest fern thrives in warmth with temperatures between 15 and 27degrees Celcius. It can tolerate temperatures down to 10 degrees, but anything colder than that can harm the plant, especially with prolonged exposure.
This fern thrives in high humidity and humid environments, such as a bathroom, greenhouse, or terrarium. To raise humidity around a bird’s nest fern, you can use a humidifier. Or, you can set its pot on a tray filled with pebbles and water. But, make sure the bottom of the pot isn’t sitting in the water because doing so can lead to root rot.
Water and Food
The ferns prefer a consistent amount of soil moisture, but they don’t do well sitting in soggy soil. Water whenever the top inch of soil begins to dry out. Avoid watering directly into the center of the plant, as this can encourage mold growth and rot in the dense nest. Aim water at the soil to avoid wetting the fern's fronds.
During the fern's growing season (September to April), feed twice a month with a balanced liquid fertiliser FabGardenMama Worm Juice Fertiliser, that's diluted to half strength. Make sure to apply the fertiliser to the soil and not the fronds. Withhold fertiliser for the rest of the year because too much food can cause the fronds to have an abnormal shape or take on a yellowish or brownish colour.
Repotting
Bird’s nest ferns are accustomed to growing with minimal potting media. So your plant generally won’t need repotting because its roots have run out of space. Instead, these ferns will need repotting once they’ve grown so large that they’re unstable in their pot and need a larger container to attach themselves to. This will typically occur every two to three years. When it’s time to repot, select the next pot size up. Carefully loosen your plant from its previous pot, and set it in the new pot, filling around it with fresh potting mix.
Bird's Nest Fern Varieties
There are only a handful of varieties of bird’s nest ferns, which typically feature different leaf shapes:
Asplenium nidus 'Crispy Wave’: sword-shaped ruffled leaves
Asplenium nidus 'Osaka’: narrow, strap-like leaves with rippled edges
Asplenium nidus 'Antiquum’: wavy leaf margins
Asplenium nidus ‘Victoria’: long, wavy, tongue-shaped fronds