Indoor Ferns: How to Grow This Natural Air Purifier at Home

    Indoor Ferns: How to Grow This Natural Air Purifier at Home

    9:55 AM EDT, August 15, 2023, updated: 5:01 PM EDT, August 15, 2023

    Ferns have been here on this planet for a long time. It is natural habitat is forest where we often come across the plant with its characteristic leaves.

    When grown at home, the plant has got its requirements. When taken care of properly, it returns the favor by purifying the air by removing such harmful substances as formaldehyde and xylene. And this should be a sufficient reason to invite ferns to our houses.

    Today we would like to give you some essential hints about how cultivating ferns.

    House fern purifies and ionizate the air. It neutralizes the harmful impact of TVs, computers and smartphones. Moreover, it improves the microclimate by neutralizing formaldehyde emitted during incomplete burning of carbon. This also makes it a perfect ally in our struggle against smog.


    The original natural habitat of house fern is the damp and shady forests of the temperate climate zone. The plant has got creeping rhizomes ending with single or feathery leaves. Young leaves are rolled like snails. The plant also grows external shoots – its aerial roots.

    Varieties of fern to be grown at home

    The Sword fern (Nephrolepis exaltata) – a very popular variety of potted fern. Its got long feathery leaves and shoots of young plants.

    The maidenhair fern (Adiantum) a small variety of fern with light green leaves shaped a bit like gingko. It spreads very fast.

    Placetyrium alcicorne is a species of staghorn fern. In natural environment it grown on fork-shaped branches or on the tree bark. It is a very spectacular plant.

    Brake (Pteris) – it's got feathery light green leaves, usually 10 – 12 inches long.

    Pellaea rotundifolia has got small round leaves.



    Ferns prefer semi shade locations. The older the plant, the more light it needs, though. Direct sunlight exposure can burn it. For the same reason it has to be kept away from any sources of heat, for example radiators. The plant does not like drafts, either.

    Soil medium

    Proper soil medium for ferns should be permeable, fertile and of slightly acidic pH (5.6). Turf with small pieces of conifer trees bark is a recommended option. Of course gardening stores offer ready-made soil dedicated for ferns.

    As frequent watering is necessary, it is also important to ensure appropriate drainage, for example using a layer of expanded clay.

    House ferns – temperature

    The best temperature range for ferns is 18 – 25 degrees C. In the winter, however, that should go down to 15 – 18.


    Ferns love frequent sprinkling and air humidifiers around. They do not like fluctuation of humidity, which should be kept between 60 and 80% at all times.

    Ferns – watering

    Ferns prefer humid environment so regular watering is welcome. The soil should be slightly moist all the time. The water, preferably soft, should be pre-boiled and left overnight before using.


    Ferns can't be repotted too often. It is recommended that they should be repotted every 2 – 3 years in the spring. They prefer ceramic pots allowing evaporating of the excess of water from the soil.



    The plant should be fertilized with dedicated agents from the spring to the fall, however never more frequently than once a month. In the winter there is no need to apply extra support, even for as long as 2 – 3 months.

    We can rely on some DIY ways to strengthen the plant, for instance by using tea extract with or without the leaves which can be buried in the soil or left on the surface. We can use tea (without any extras) even once a week.


    The spring is the best moment when ferns can be 'divided' into a few new seedlings. All you need to do is to split the root ball. You can also propagate it using young plants appearing on the shoots.


    Ferns can be trimmed. This is how we remove dead leaves for example. You can also remove old leaves, cutting them off at the base. Ferns regenerate wonderfully and soon look much younger. Some gardeners believe that the aerial roots can be trimmed, too.

    Fern diseases

    Dying leaves are a symptom of inappropriate care. Knowing that ferns like water, we tend to exaggerate with our watering cans.

    When the leaves go yellowish and fade, it means that the plant has been overwatered and its roots could be dying.

    The tips of leaves go brownish and dry when the ambient humidity is too low.


    Fungus love moist environment where ferns feel good, too. No wonder then that fungus, for example Alternaria, Colletotrichum or Phyllosticta, attack the plants and cause stains on the edges of the leaves. You have to quickly react once you notice that symptom – get appropriate anti-fungus agent and spray it on the plant.


    When the temperature is high and the humidity too low, the plant can be infested with armored scale insects (Diaspidida) and spider mites/

    Armored scale insects cause yellow leaf stains with a sticky substance they leave behind. To remedy that you have to rinse the leaves with water with household soap or denaturated alcohol to kill off the insects.

    Spider mites form a kind of web. A standard pesticide is enough to get rid of them.

    Springtails – whitish tiny insects living on the pot soil. If you find them in your fern pot, you have got to repot it. You can also use dedicated fertilizer-pesticide sticks.

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