A Bird's Nest Fern With Brown Leaves

Natural Browning

• The bird’s nest fern is a tropical plant that requires loamy, acidic soils with pH levels between 5.0 and 5.5. It is not tolerant of drought and requires a continuously moist, but never saturated, soil environment in humid climates that range between 70 and 90 degrees Fahrenheit. In these ideal conditions, the bird’s nest fern produces many dark-colored spores on the undersides of its leaves that it uses to produce more leaves. This browning is centralized down the center veins and should not be mistaken as ailing or browning foliage.

Tip Burn

• A combination of drought conditions and excess nutrients can cause the bird’s nest fern to develop tip burn, in which the foliage develops brown, necrotic areas around the tips and margins. To correct the condition, leach the soil of all nutrients and take a soil sample to read the medium’s acidity levels. Feed the fern to bring the soil’s pH level back to between 5.0 and 5.5. Irrigate the soil regularly to maintain a moist, but not saturated, soil environment. Take a soil sample before each scheduled fertilization to avoid overfertilization and resulting tip burn.

Bacterial Blight

• Bacterial blight is a spore-borne disease that is most aggressive during humid, moist conditions. Since the bird’s nest fern grows best in the same conditions, it is important to take regular steps to prevent bacterial blight infections. The infectious spores develop on defoliation that lies around the tree and are transported by wind and rain. The infection causes the bird’s nest fern’s foliage to develop small, water-soaked spots that develop into larger, reddish-brown lesions that decay the tissue. Bacterial blight spores require the presence of water in order to infect the foliage. Always irrigate the bird’s nest fern at soil level in efforts to keep the leaves dry. Avoid misting and humidity trays, and always keep the bird’s nest fern’s planting area free of debris and defoliation.

Foliar Nematode

• Foliage nematodes are destructive organisms that feed on the tender tissue that lies around the bird’s nest fern’s base. The tiny organisms are nearly impossible to see with the naked eye; however, the symptoms of the nematode feedings are quite clear. The nematodes feed on the interior tissue of the lower leaves and exits only to find new interior areas to feed. The feeding causes the fern’s foliage to develop brown to black decaying lesions around the base of the plant. Removing nematode infestations is quite difficult because the pest can take shelter in the fern as well as its soil, potting container materials and crevices. It is always best to discard the infested bird’s nest fern, its container and soil to prevent further infestations.