DISCOVER
×

Trees & Rust Fungus

Trees can get a variety of fungal diseases, which are unattractive and sometimes damaging to the trees. Rust fungus gets its name from its rust-coloured appearance. Different types of rust fungi infect different tree species.

Types

Different types of rust fungi usually have names that include the type of tree they infect. For example, some varieties include ash rust, cedar-apple rust, pine stem rust and white pine blister rust.

Appearance

In general, rust fungus has a yellow, orange or red rusty colour. Ash rust and cedar-apple rust show up as rusty spots on the tree's leaves. White pine blister rust and stem rusts show up as growths or rust-coloured wounds on tree branches or trunks

Effects

Rust fungus may kill some branches on conifers. Ash rust usually does not damage a tree severely, but it can make it more likely to sustain damage from cold winter temperatures. Apple-cedar rust can damage fruit on apple trees.

Prevention/Solution

Fungicide sprays can help kill rust fungus, and gardeners can prevent the fungus by making sure to purchase healthy trees from certified nurseries.

bibliography-icon icon for annotation tool Cite this Article

About the Author

Lisa Chinn developed her research skills while working at a research university library. She writes for numerous publications, specializing in gardening, home care, wellness, copywriting, style and travel. Chinn also designs marketing materials, holds a Bachelor of Science in psychology and is working toward a PhD in cognitive neuroscience.