Staghorn ferns (Platycerium bifurcatum) can be difficult to grow. They grow as houseplants or outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 12. Fuzzy brown stains on the fronds might have you worried, but they might be perfectly normal areas of the staghorn fern’s life cycle. An incorrectly watered staghorn fern may also develop creamy brownish spots on the fronds.
Fertile Fronds
Unlike flowering plants, staghorn ferns do not reproduce by seeds. Instead staghorn ferns send out thousands of powdery spores to be carried by the wind. The spores develop on the undersides of their lengthy, pronged fronds that provide staghorn ferns their title. Small across brown bumps, called sporangia, kind across the fronds. They can look or feel fuzzy, particularly when they have opened to release the seams.
Sterile Fronds
The staghorn fern additionally has plate- or shield-shaped fronds. These fronds do not produce seams — their aim is to hold the staghorn fern into the tree. As they age, those fronds develop creamy brownish stains, eventually turning entirely brown and dry. They’ll be replaced by new, green fronds as a natural part of the plant’s growth. These spots should not be a cause for anxiety, and will be the equivalent of dropping old leaves in favor of new ones.
Thirsty Fronds
A badly watered staghorn fern may also develop creamy brownish stains. If the stains are on the tops or tips of the fronds and spread so the entire frond starts to turn brown, then the staghorn fern was under-watered and is drying out. It’s normal for a few fronds to turn brown and die, then be replaced with new fronds. If more fronds are demonstrating brown stains than are completely green the root ball of this fern has to be soaked for several minutes to permit the plant to absorb water.
Wet Fronds
Fuzzy brown spots that turn black indicate the staghorn fern has developed a respiratory disease, most commonly rhizoctonia. Letting the staghorn fern to dry out slightly between waterings may remedy this kind of problem. Removing contaminated fronds can also help stop the fungus from spreading to healthy fronds.