Diseases are one of the most common plant problems when it comes to landscaping. It can be challenging to identify because the naked eye rarely sees the organisms that cause infection.

Tree diseases affect any part of the tree as well as it can change the entire specimen. Due to the numerous amounts of conditions, it is essential to identify what the specific disease is and to take corrective action. Diagnosis is the first step to curative treatment, and it will allow you to address the problem instead of merely treating the symptoms directly. Times like this is when you should seek the diagnosis of a professional and licensed arborist.

Below are a few of the tree diseases that affect most existing plant life.

  • ​Dutch Elm Disease (DED): a disease caused by a member of the sac fungi affecting American Elm Trees. The fungus clogs the vascular tissues restricting water movement this causes the tree to wilt and eventually die. Dying branches are one of the symptoms of DED and the best way to diagnose it is by cutting a live branch to check if there is brown streaking inside sapwood.
  •  Tree Blight: Symptoms include wilt and browning of leaves in significant sections of the tree. A bacteria or a fungus causes this disease.
  •  Leaf Spot: Dead tissue that looks like small spots on leaves
  •  Fire Blight: Mostly affects Apples and Pears, and is caused by bacteria.
  •  Blotch: Caused by a type of fungus that creates blotches of black or brown to appear on leaves, these will appear larger than leaf spots.
  •  Scab: Scabs appear on the fruit of Apple trees, it slowly shows up as lesions on the leaves then gradually develops into a cracked or hardened scab on the fruit.
  •  Canker: A fungi that form necrosis on the tree’s branches and bark.
  •  Hypoxylon Canker: This fungus mostly affects Oak trees, and will result in necrosis in the bark. This disease is induced by drought and is very easy to identify. Plants affected by this will have barks with a pale greyish color.
  •  Leaf scorch: Affects a wide variety of tree species and is commonly caused by weather extremities. Symptoms include the browning of dead areas of a leaf specifically along its edges.
  •  Verticillium Wilt: A soil born fungus infects the wood and vascular system of the tree. Symptoms include the infected area having discoloration in streaks with yellow and wilting leaves.
  •  Oak Wilt: insects spread a fungus through the roots, which only affects Red Oaks. Symptoms include leaf discoloration, wilting leaves, and defoliation.
  •  Pine Wilt: This disease is spread by a beetle named Pinewood Nematode. When they chew on phloem or when the female lays its eggs in the wood. This disease results in browning and the dying out of needle in large sections or the entire pine tree.
  •  Armillaria Root Rot: Commonly called “Shoestring Root Rot,” it results in mushrooms growing on rotten wood. This disease spreads by root-like structures called Rhizomorphs.

These are just a handful of the diseases that affect trees and plants alike, but with the proper care and healthy environment, they can be treated or avoided.

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