Cedar Apple Rust Treatment: How to Stop Tree Fungus Disease

Are there small, reddish-brown bumps growing on the branches of your cedar trees? Do the leaves on your apple trees have yellow spots? If so, your trees could be infected with Cedar Apple Rust. Read on to learn more and how to stop Cedar Apple Rust.

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What is Cedar Apple Rust?

Cedar Apple Rust is a fungal infection that could harm your apple trees if left untreated. According to the University of Wisconsin, “several fungi in the genus Gymnosporangiumcause Cedar Apple Rust.” As its name implies, the disease needs two host plants to complete its life cycle: cedars and apple trees. The fungus lives part of its two-year life cycle on cedar trees, most commonly the Eastern Red Cedar. Then, infected cedars release spores into the air that travel to the buds and leaves of nearby apple trees. The fungus spends the second part of its life on apple trees.

How do I Recognize Cedar Apple Rust?

Cedar Apple Rust on Cedar Tree

Cedar Apple Rust on Cedar Trees

Round, brown bumps, or galls, about 1/2 to 2 inches in size will be found on the branches of your infected cedars in the spring. The galls develop slowly during the summer and remain on the cedar trees during the winter.

Next spring, rain causes bright orange horns or tendrils to grow on the galls. Your cedars will look like they are blooming with orange, tropical flowers.

Cedar Apple Rust on Apple Tree Leaf

Cedar Apple Rust on Apple Trees

Yellow spots with black dots in the center will appear on the upper surface of the leaves of your apple trees. The spots will enlarge and develop a reddish border. Eventually, small brown tubes will appear on the underside of the leaves. These tubes release spores that will search for cedar trees to start the disease cycle again.

How Can I Get Rid of Cedar Apple Rust?

Generally, cedar apple rust is not harmful to cedars. However, your apple trees can suffer greatly from the infection. Leaves and fruit may fall off the trees prematurely, and the apples could have yellow spots or be inferior in quality.

Since 1968,  M&M Tree Care has been caring for trees in the Milwaukee area. We can help you control cedar apple rust on your apple trees by applying three annual spring treatments of fungicide. To help your apple trees recover from cedar apple rust and to improve their condition, M&M Tree Care also recommends applying organic fertilizer. Contact M&M Tree Care at 414-355-3420 so we can help save and care for your cedar and apple trees.