Ferns are ancient plants that are about 300 million years old. They don't flower or bear fruit, but instead reproduce via tiny spores on the undersides of their leaves. Ferns are low-maintenance plants that are easy to grow as houseplants or as outdoor ornamental foliage. While pests don't pose a large problem to ferns, certain pests can damage the health and appearance of even the most vigorous varieties.
Mealy bugs suck the nutrients and moisture from your ferns. These pests are white and covered with waxy threads that help protect them from predators. Mealy bugs usually feed on the joints between the leaves and the stems or on the leaf veins themselves, which causes the leaves to turn yellow and fall from the plant. Cut off infested fern branches to help control the spread of mealy bugs to other parts of your plant. Remove individual mealy bugs by dotting them with a cotton swab dipped in rubbing alcohol. A solution of 10 percent rubbing alcohol and 90 percent water can be sprayed directly onto the fern for heavier infestations of mealy bugs. Handpicking mealy bugs is another way to get rid of them.
Nematodes are worms that can cause devastating damage to plants and crops. They are very small, which makes it challenging to spot them before they cause any damage. Certain types of nematodes cause damage to the roots from underground, which can cause lesions, stunting or wilting of your fern plant. Foliar nematodes live on the leaves of your fern plant and cause lesions and deformations of the leaves. Foliar nematodes can also cause fern leaves to become discolored. It is difficult to get rid of nematodes, but removing infested leaves and repotting your fern can help. If this is unsuccessful, your fern plant will have to be thrown away.
Fern mites are difficult to detect because they are so small. It is more likely that you will know that fern mites have infested your plants by the damage they cause. Fern mites can damage most species of fern by feeding on leaf tissue. Over time, this can cause stunted leaf growth and deformed leaves. Fern mites can also cause the leaves of the fern plant to become bronze or rusty colored. Insecticides are often useful in getting rid of fern mites. Keep the infested fern away from other ferns to prevent the mites from spreading while the insecticide works.
Aphids can infest almost any type of plant, including ferns. Rinse your fern plant under running water to dislodge the aphids. Scales, a microscopic and hard to detect insect, can also infest your fern plant and cause it to die back. A rubbing alcohol spray, diluted to one-tenth alcohol and nine-tenths water, or soap sprays can destroy scales before they cause damage. Thrips leave behind dark spots and can cause leaf distortion and scarring of petals. Soap sprays can eliminate thrips from your ferns. Pick snails off your ferns with your fingers because they can cause devastating damage to your plants.
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