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Trees & Root Fungus

By Cleveland Van Cecil ; Updated September 21, 2017
A healthy set of roots keeps a tree standing tall.

Trees are only as strong as the root system that give them sustenance and hold them aloft. Unfortunately, there are a host of fungus varieties that seek out the roots of weak trees for sustenance, causing a tree to become sick, and in some cases, die off.

Root and Butt Rots

Root and butt rots are wood decay diseases causes by fungus that get into the tree by way of wounds in the lower part of the tree or get into the roots. The fungus will attack the cambium, part of the inner bark, and can kill the tree if it spreads all around the tree. Fungus will also attack the inner wood in the stem, which can cause the roots to become weak and uprooted.

Vascular Wilts

Fungus can attack in the roots and spread into the vascular system of the tree, causing what is called vascular wilt. This causes the tree to exhibit drought-like symptoms, as the tree wilts and becomes dry.

Signs and Symptoms

Root diseases tend to look like mineral deficiencies in the plant as root problems tend to limit the amount of nutrients and water that can be absorbed by the roots of the tree. Foliage of the plant may shrink, become yellow and fall off. White fungal growth may appear at the bottom of the tree as well. Sometimes symptoms only show up years after the infection occurs.

Controlling Fungus

Prevention is the best control for fungal infections in trees. A healthy root system will keep fungus from attacking. The root system requires enough room to grow in the dirt, planted 16 to 24 inches deep in nutrient-rich soil. Watering once a month during dry winters prevents the tree from becoming weak, making it susceptible to infection.

Killing Fungus

Fungal infections are hard to kill once the infection has occurred. If the infection is caught early, a fungicide may be applied to the dirt to control spreading and prevent further damage. However, if the tree has been infected in the vascular system, it is not likely the tree will recover.