Staghorn Fern With Brown Tips

Reproduction

• The spores of staghorn fern are on the frond tips and along its forked branches in cases, called sporangia. Because immature spores are initially green, they are hard to see. But as the spores mature, they turn brown and give frond tips a rusty appearance because that is where they're most numerous. At maturity, the sporangia burst open and expel the dustlike spores, removing the brownish cast on the leaves and restoring the fronds to a uniform green color.

Humidity Problems

• Staghorn fern’s native habitat is in the humid jungles of Australia, Polynesia and Southeast Asia where it grows attached to trees. Although its roots must drain freely, staghorn's fronds need high humidity. If humidity is low, its frond tips and margins turn brown. Staghorn fern fronds have a covering of white felt, which is an adaptation to help the plant capture and retain humidity. If you grow your fern in a dry area, mist this white felt daily to help keep the fronds green.

Temperature and Light Problems

• Staghorn fern grows outside in U.S. Department of Agriculture plant hardiness zones 9 through 12. In cooler climates, you can grow this plant in baskets or on wooden plaques so you can move it inside during cold weather. Frost and freezing temperatures burn the fronds and turn them brown, after which plants may not recover. Imitating its native habitat under jungle canopies, staghorn fern flourishes in shady spots that get only filtered sun. Full sun is too harsh and burns plants, causing their leaf tips and margins to turn brown.

Insecticide Problems

• Staghorn fern is relatively pest-free, although mealybugs and scale insects may be occasionally bothersome. But don't be too quick to reach for the nearest insecticide because it may leave a brown chemical burn on staghorn's fronds. Its sensitivity to insecticides is not a problem if you remove the pests by hand. If you're squeamish about touching insects, use a milder water-based insecticide, such as ready-mixed insecticidal soap, instead of an oil-based product. Follow all label directions and use sparingly because of staghorn's insecticidal sensitivity. Test an inconspicuous leaf with the product and check it 48 hours later for signs of damage before using the product on the entire plant.