Diseases Diseases

About Ash Tree Diseases

Published at 04/05/2012 22:50:00


Ash trees are tall, fast growing, hard wood deciduous trees that are resistant to extreme weather conditions. They thrive well on all soil types and shed their leaves seasonally. They’re known for their compound leaves (with 5-6 leaflets present around the main mid rib) and high quality wood. The wood obtained from this tree is used for manufacturing furniture, handles, sports equipment and frames of door and windows. Despite of having resistant features, ash tree diseases are widespread all over the world.

The American continent has approximately 65 recognized members of this species, green and yellow ash being the prominent ones. Both these varieties can succumb to different ash tree diseases. These diseases may occur because of microbial agents, aphids, worms or changing weather conditions. While some are curable, others are not.


Mentioned below are some common ash tree diseases that generally affect all the living varieties:

1) Verticillium Wilt: It is a root disease caused by fungi species that inhabit the water conducting tissues (xylem) of the tree’s roots. Common symptoms include discoloration, sapwood streaking, peeled bark and wilting of young roots. A fully infected tree can die within 1.5-2 years. Root injuries and lack of nutrients in the soil can contribute to the spreading of this disease to other parts. This is one of the commonest ash tree diseases and instant care should be taken to prevent it from getting worst.

2) Anthracnose Disease: Ash tree diseases like Anthracnose generally affect the main foliage although sometimes other aerial parts like twigs, side branches and blooming buds might also get affected. Leaves of infected plants wither away prematurely. Other common symptoms include formation of brown to black narcotic spots, cankers and permanent dead tissues on leaves. These signs are common during onset of summers or late springs.

Even though the disease is not fatal, severe defoliation can weaken the trees and make them vulnerable to worse conditions like seasonal allergies, environmental stress and pathogen attacks.

3) Aphid Attacks: Attacks from aphids like Carpenterworms can damage tree trunks and aerial parts. Most aphids bore through sprouting shoots and colonize inside the trunk or branches of green ash resulting in oval scarring. Ash tree diseases caused by insects can be treated at any stage by making use of appropriate insecticides.


4) Ash Yellow: These types of yellowing ash tree diseases affect the green varieties only. It arrests the plant growth and cause wilting as well as loss of chlorophyll from the aerial parts. This disease was first discovered in the year 1980 and was said to occur as a result of droughts, environmental factors and parasitism. Mycoplasmas and leaf hoppers may also cause them.

5) Microbial Infection: Microbial infection cause by fungi and other agents cause bulges, swelling, hollows or narcotic spots on the tree. It can make trees brittle and weak.

Tips and comments

In case your garden plants are being affected from ash tree diseases, you must immediately consult a nearby nursery or plant center for immediate advice. Eliminate the diseased part, use insecticides on the fresh green parts and take proper care to keep them protected.