The sword fern (Polystichum munitum) is native to the Pacific Northwest region of North America, where it grows in dense stands in forests and along streams. The fern has also been introduced to other areas, including the United Kingdom and New Zealand, where it has become naturalized.
Habit: Upright to arching medium to large sized clumping perennial up to 90 cm tall and wide with green to greenish-yellow fronds that can be feathery to frilly.
Temperature: Plants grow best between 15 to 25ᐤ C and temperatures below 4ᐤ C may result in the death of the plant. Avoid placing plants in windy or drafty locations which can lead to less attractive plants. Misting plants regularly in dry, low humidity periods will keep it looking good until conditions change.
Light Exposure:Sword ferns prefer bright, indirect light. They can tolerate some direct sunlight, but too much can damage the fronds. If your fern is not getting enough light, it may become leggy and lose its vigor. You can provide additional light by placing it near a window or using grow lights. When placed in too dark of a location, leaves will yellow rapidly and fall off and plants will decline.
Watering: Sword fern likes a moist growing medium but not soggy; water only when the top 3 cm of soil feels dry to the touch. Always check the soil moisture first but as a rule of thumb watering once or twice a week in the rainy season, once every two or three weeks in the cold dry season and twice a week in the hot dry season.
Humidity: Sword ferns prefer humid conditions and will appreciate a daily misting. You can also increase the humidity around your fern by placing a tray of water nearby or using a humidifier.
Fertilising: Give plants a well balanced fertiliser once a month during the hot dry season and rainy season but not during the cold dry season when plants are resting (semi-dormant).
Pruning/Repotting: Remove yellow or dried frond leaflets or entire fronds as needed. Plants can grow fairly quickly and crowd the pot within a year and can then be divided by cutting it in half and potting up each piece.
Pest Control: Sword ferns are relatively pest-free, but they can occasionally be affected by spider mites, mealybugs, and scale insects. If you notice any signs of infestation, such as yellowing leaves or sticky residue, treat your fern with a natural insecticide or insecticidal soap.
In conclusion, sword ferns are hardy and adaptable houseplants that can thrive in a variety of conditions. By providing them with the right amount of light, water, fertilizer, and humidity, you can enjoy their lush green fronds for years to come.