how to get rid of rust on bald cypress tree

How to Get Rid of Rust on Bald Cypress Trees

Rust is a common fungal disease that can affect many tree species, including the iconic bald cypress tree. This disease manifests as yellow, orange or reddish-brown powdery pustules on the leaves, twigs and branches of infected trees. If left unchecked, rust can weaken and deform bald cypress trees, causing leaf drop and dieback. Fortunately, there are several effective treatment methods available to get rid of rust on your prized bald cypress trees.

Identifying Rust on Bald Cypress Trees

The first step is learning how to identify rust disease Look for the following symptoms

• Powdery growths on the undersides of leaves or green stems. These pustules produce masses of reddish or yellow spores.

• Discolored spots on foliage, ranging from yellow to orange, reddish-brown or black.

• Premature leaf drop, starting from the lower branches.

• Stunted twig and leaf growth.

• Dead branches and branch tips.

• Cankers or sunken areas on branches and stems.

Rust thrives in warm, humid conditions. Inspect your trees carefully after periods of wet weather. Check both leaf surfaces as well as stems and branches. Early detection and prompt treatment offer the best chance of managing rust infections.

Cultural Control Methods

The following cultural practices can help prevent or reduce rust fungus growth:

• Improve air circulation around trees through proper spacing and selective pruning. Thin out overcrowded branch areas.

• Water bald cypress trees early in the day so foliage dries quickly. Avoid frequent overhead watering.

• Apply mulch around trees to prevent soil splashing onto lower leaves.

• Rake up and dispose of fallen leaves, twigs and branches. These harbor spores that spread rust fungus.

• Fertilize trees appropriately to maintain vigor without forcing succulent growth.

• Monitor for signs of rust and promptly remove any infected plant parts.

Chemical Fungicide Sprays

If cultural methods alone cannot control a rust outbreak, fungicide application may be warranted. Some effective chemical options include:

• Chlorothalonil – Broad spectrum fungicide that prevents spore germination. Use liquids like Daconil.

• Myclobutanil – Systemic fungicide that stops fungus growth. Trade names include Eagle and Spectracide Immunox.

• Tebuconazole – Also systemic, providing rust control for several weeks. Products contain Folicur or Banner Maxx.

• Copper fungicides – Broad spectrum fungicides that inhibit spore production. Brands include Bonide Copper and Liquid Copper.

• Neem oil – Derived from the Indian neem tree, this fungicide coats leaves in a suffocating film to control fungal disease.

• Bacillus subtilis – This biological fungicide helps protect plants and stimulate natural defenses. Serenade Garden Disease Control is one brand name.

Take proper safety precautions when handling and applying chemical fungicides. Avoid contact with skin and eyes. Follow all label directions carefully regarding dilution rates and permitted applications. Test a small tree area first to ensure plant compatibility. Rotate between fungicide classes to discourage resistance. Treat when rust first appears and reapply every 7 to 14 days if needed. Spray thoroughly to coat all leaf and stem surfaces.

Miticide Treatment

Rust mites can sometimes resemble rust fungus on bald cypress foliage. Broad spectrum miticides like carbaryl (Sevin) can eliminate rust mite infestations. However, pesticides also kill beneficial insects that help control other bald cypress pests. The Missouri Botanical Garden generally recommends against miticide use unless mite damage is severe. Instead, rely on natural predatory mites and insects to keep rust mites in check. Proper tree care and maintenance helps minimize mite outbreaks.