Wednesday, April 6, 2011

Trees Alert: Spring Tree Diseases and How to Avoid them

It’s spring time once again. Spring is that time of year when trees and flowers begin to bloom and show off their lovely leaves again. Even if it is one of the most wonderful time of the 4 seasons we encounter we have to consider that there are certain diseases that also show up on our plants and trees. Trees, in particular encounter certain fungal growths that can affect their lives. Let’s try to have a look at some of the diseases that we may encounter with our trees:

Aspen Leaf Spot
Manner of spreading: wind and rain

Damage done: Attacks the leaves as they begin to emerge in the spring.

Appearance: Small dark spot on leaves, less noticeable during late spring and early summer, as summer progresses, the spots enlarge and look like will envelope all the leaves and even the entire tree.

Host Tree: Aspen

Cause of Severe infestation: Defoliation of leaves, leaving the tree vulnerable to other diseases and insects. The tree becomes unappealing which may lead to the tree's death by natural cause.

Treatment: Treatment should be done early spring. Spray or apply a registered fungicide like Daconil on leaf spot that's on the label. Follow the directions as indicated on the label.


Manner of Spreading: Happens during springtime, unnoticed and manifests in summer when treatment becomes impossible.

Damage done: Their damage is similar to what leaf spots can do and when you start to notice them, the tree becomes impossible to save.

Appearance: They look like small spots of leaves that appear to be watery.

Host tree: Maples, sycamores, oaks and ash trees.

Cause of Severe infestation: The small spots on the leaves initially appear on the leaves. They become bigger and turn to red, brown or black. The infection can go to the petiole of the leaves and will infect small branches. The more grave the infection, the leaves defoliate and will cause small branches and twigs on the tree to die.

Treatment: The treatment is similar to the control process done on leaf spot. Aside from using fungicide, the leaves that drop during fall season should be raked and burned. Sycamore trees may be too large to spray fungicides, it is best to use the service of tree services to get it done.

Fire Blight

Manner of Spreading: This is not a fungal disease but rather a bacterium

Damage done: The leaves on the tree wilt and dry. They turn black and look like they are scorched.

Appearance: When you examine the affected area very closely, you will see a whitish cream or reddish-colored leak coming from the tree's wounds. The leaves will indicate they are infected by these bacteria through the leaves’ twigs. They take on a shepherd's crook shape when they start wilting.

Host tree: They infect pears, apples cotoneasters, hawthorns, pyracantha and mountain ash trees and shrubs.

Cause of Severe infestation: The bacteria spread during warm, wet springs. Insects carry the bacteria from flower to flower. They spread to the twigs of the infected flower. Severe infection of these bacteria can destroy a pear tree in one season.

Treatment: When you notice any signs of this in early summer after the flowers bloom, the only way to stop it from spreading is to cut-off the infected wood. They should be cut at least 8 to 12 inches below the infected part and remove the wood from the area or orchard.

Make sure that you are on a look out for these spring diseases especially when your trees or vegetation are in bloom. When there is less rain or lack of moisture around during seasons of bloom then treatment isn't needed. When the spring weather becomes warm and wet during blooming season then take necessary precautions.

1 comment:

  1. Remove the wood from the orchard before any other trees or shrubs around it are infected from the ash die-back. Ash die-back is extremely deadly to certain tree species, don't let it creep up on your garden!

    -Samudaworth Tree Service
    Tree Pruning Brooklyn