Plant diseases can spread rapidly and cause significant damage if left unchecked. Our Disease Management service provides comprehensive monitoring and treatment to safeguard your plants against infections caused by fungi, bacteria, and viruses. We regularly inspect trees and plants for early signs of disease, such as discoloured leaves, unusual growths, or decay.
Based on our diagnosis, we apply targeted treatments, including fungicides, bactericides, and pruning techniques, to contain and eliminate pathogens. Our proactive approach helps prevent the spread of disease while strengthening the plant’s natural defences, ensuring a healthy, thriving landscape.
Brisbane’s subtropical climate is conducive to a wide variety of tree species, but it also creates conditions where several common tree diseases can occur. Here are some of the most common tree diseases that affect trees in Brisbane:
Pine Needle Blight (Dothistroma septosporum)
Affected Trees: Primarily pine trees (e.g., Hoop Pine, Radiata Pine).
Symptoms: Yellowing and browning of pine needles, followed by premature needle drop. Infected trees may become sparse and stressed.
Cause: Fungal infection, spread through the wind or rain. Often exacerbated by wet or humid conditions.
Management: Remove and destroy infected needles, prune affected branches and apply the appropriate fungicide treatments where necessary.
Root Rot (Phytophthora spp.)
Affected Trees: A large variety of both native and imported tree species.
Symptoms: Yellowing or wilting leaves, dieback, stunted growth, and root decay. Infected trees may exhibit an overall decline in health in all areas.
Cause: Fungal pathogens that thrive in waterlogged or poorly drained soils. Spread through contaminated soil or water.
Management: Improve soil drainage, avoid overwatering, and remove affected roots. Fungicides may be used but preventing it from occurring in the first place is key.
Canker Diseases (Various fungi)
Affected Trees: Eucalyptus, Acacia, and other native species.
Symptoms: Sunken, discoloured lesions on bark or stems, gum oozing, and dieback in affected branches. Trees can become structurally weakened and may eventually die.
Cause: Fungal infections, often entering trees through wounds or natural cracks in the surface of the bark. Stressful environmental conditions can increase susceptibility.
Management: Prune out infected areas, avoid wounding trees further and ensure proper care and watering.
Leaf Spot (Cercospora, Colletotrichum, etc.)
Affected Trees: Many ornamental trees, such as Jacaranda, Mango, and Sycamore.
Symptoms: Round, dark spots on leaves, often surrounded by yellowing tissue. This can lead to premature leaf drop.
Cause: Fungal infections, typically spread by the rain and wind.
Management: Prune affected leaves, avoid overhead irrigation, and apply fungicides if needed.
Gall Wasp Infestation (e.g., Eucalyptus Gall Wasp)
Affected Trees: Eucalyptus species.
Symptoms: Swelling or galls on leaves, stems, and branches. In severe cases, galls can affect the growth and health of the tree.
Cause: Small wasps lay their eggs in the tree tissue, which causes the plant to form galls as a response to the larvae.
Management: Prune infected branches and destroy them. Although in many cases, infestations may subside naturally.
Powdery Mildew
Affected Trees: Various tree species, including guava, crepe myrtle, and roses.
Symptoms: White, powdery fungal growth on leaves, stems, and buds. Infected leaves may curl, yellow, or become distorted.
Cause: Fungal pathogens that thrive in warm, humid conditions.
Management: Prune affected areas, apply fungicide treatments, and improve air circulation around trees.
Anthracnose (Colletotrichum spp.)
Affected Trees: Eucalyptus, Mango, and some tropical species.
Symptoms: Dark, sunken lesions on leaves, branches, and fruit. Can cause dieback and premature leaf drop.
Cause: Fungal infection, often exacerbated by wet, humid conditions.
Management: Prune infected parts, remove fallen leaves and fruit, and apply fungicides as needed.
Fungal Root Diseases (Armillaria, Ganoderma)
Affected Trees: Many tree species, including both native and exotic trees.
Symptoms: Root rot, fungal fruiting bodies near the base of the tree, slow decline in the general health of the tree and premature leaf drop.
Cause: Fungal pathogens that attack the root system, weakening the tree and causing it to decline over time.
Management: Improve soil drainage, remove infected material and practice good tree care to reduce stress.
Prevention & Care
Proper Tree Care
Regular pruning, watering, and fertilization can help prevent tree diseases. Healthy trees are less susceptible to pests and pathogens.
Monitoring
Inspect your trees regularly for early signs of disease and act quickly.
Fungicides & Pesticides
When necessary, the use of fungicides and pesticides can help control disease spread. Always follow the manufacturer’s instructions.
Environmental Management
Good garden hygiene, proper irrigation practices, and avoiding over-fertilization can help reduce the likelihood of disease outbreaks.
If you notice a disease spreading rapidly or affecting the structure of your trees, it is a good idea to consult an arborist or local horticulturist for professional advice and treatment options. If you’re worried about the health of your trees, you can contact us here for professional help.