If your Boston ferns are turning brown, investigate the probable causes and understand the possible cures. The Boston fern, or the Nephrolepis exaltata plant, is among the most commonly-grown of landscape and potted plants. Use the following information to revitalize your Boston ferns.
Watering & Sunlight Mismanagement
Boston fern doesn’t need intensive supply of water. In fact, slight excesses of water too can harm the plant. To ensure that you are maintaining the balance of moisture supply, spray the plant repeatedly using a mist sprayer rather than repeatedly watering it. During periods of low humidity, Boston ferns tend to curl-up and turn brown. This is a typical situation that can be solved with misting the plants rather than watering them.
When watering the plant, test the top layer of soil in the pot. The top layer should be considerably dry. The slightest of over-watering can cause unwarranted damage to a developing Boston fern. Ensure that the soil is not tightly compacted, as this slows the drainage of water. Use a gardening tool to till the potted soil.
Ensure that the plant is getting sufficient but limited sunlight. This might be confusing for some folks. Boston ferns don’t react well to bright sunlight for extended hours as this can literally scorch the plant. Ensure that you place the pots in an area that is slightly shaded. If this is not possible, move the plant to a shaded area after exposing it to bright sunlight for a couple of hours.
Among plant diseases, fungal infections like the Pythium root rot is the most common cause of gradual decay of Boston ferns and its increased browning. The fronds of such plants are significantly shrunken in size. The foliage seems to wilt and the plant’s overall growth is stunted. The base section of the plant may show extremely dark brown spotting. You can cure such plants by using anti-fungal sprays and re-potting the plant with new soil.
Mites are another probable cause of brown spotting among Boston ferns. Mites are hard-to-detect. You can use a magnifying glass to see if these pests have infected the plant. You can control the infestation by wiping the mite-afflicted areas with an alcohol-dipped cotton swab. Further, spray the entire plant with an all-purpose insecticidal spray.
You need to be careful about the fertilization needs of Boston ferns. These plants need limited fertilization during certain phases. For instance, when it seems that the plant is overwhelmed with dried or brown foliage, stop fertilizing it. Resume the fertilization only when you have systematically pruned the plant. Ideally, fertilization should be done only when the new fronds are emerging. During fertilization, ensure that you provide a few nitrogen-rich sources like fish oil mixes.
You need to prune the brown, dead foliage of the plant. Take care to prune the older fronds only. The mature fronds are often called sword ferns and naturally turn brown after a certain period. This is not indicative of any nutritional or water-based problem with the plant, i.e. you merely need to remove the brown foliage to restore the aesthetics of the plant. Use sharp scissors for pruning the fronds at their base.