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A Guide to Tree Diseases and their Symptoms


There are countless species of tree in New Zealand and some are more susceptible to disease due to soil quality, climate, water levels or location. Many tree diseases go unnoticed, especially for those who aren’t avid gardeners and only notice problems when they see signs of significant decay. In this article, we’re taking a closer look at the symptoms of pathogens and pests in trees.

Bacteria and Fungi

There are many types of bacteria and fungi infestations, presenting themselves in all shapes, sizes and colours. Without the help of a professional, it can be incredibly difficult to pinpoint which pathogen is responsible for the symptoms in your tree or shrub. Thankfully, there are certain signs to look out for that will determine the health of your garden.

What to Look Out For

Bacteria and fungi symptoms can grow randomly across the whole tree or shrub. A clear indicator is the appearance of wilting leaves, drooping downwards and turning a dull, brown-grey colour. The presence of cankers (sections of dead bark which appear along the trunk) indicates a nutrient blockage which is usually transported from the roots upwards.

Root rot and decay also suggest the presence of pathogens and, if identified early, can be treated before a complete blockage of nutrients and water to the canopy kills the tree entirely.


Tree pests usually come in the form of an insect or worm which may present in some species and not in others. Beetles dig into and infect the bark of the tree while building tunnels throughout the branches. In citrus trees, a species of wasp commonly lays its eggs in the branches, causing the tree to swell and create more space for the infestation. Although these are just two examples of common pests in New Zealand, the simple fix across all infestations is fast branch and tree removal.

Visible Symptoms

First and foremost, the most obvious indicator of a pest infestation would be seeing the insect with your own eyes, confirming any doubts you may have had. Some other common symptoms of pest infestations include discolouration, curling, spots and holes in leaves. Branches may look dull and become fragile, making them susceptible to breaking and falling. The tree’s trunk may look cracked and be flaky, signifying poor health and a lack of nutrients.

How to Prevent your Tree Contracting a Disease

Regular maintenance, including trimming, pruning and watering, is the surest way to find and eradicate problems early. Hiring a professional arborist will take the stress out of maintaining your garden when you don’t have the time. At Heaven Contracting, we offer complete maintenance, including tree trimming services, tree pruning services and tree removal when necessary.

To make an appointment or to speak to one of our friendly arborists in Auckland and the surrounding suburbs, call us now on 027 475 2445. For more information on our additional tree services, visit our website today.

Tree Removal North Shore:            09 442 5350

Tree Removal Central Auckland:  09 629 2640 

Tree Removal West Auckland:       09 833 7187

Tree Removal East Auckland:        09 577 4260

Tree Removal South Auckland:      09 268 7910

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