What is cypress canker?
It is a fungus which is spread by wind-blown spores. The spores can also be spread by rain splash and birds and insects. The cambium tissue is attacked, leading to cankers or splits in the bark. Resin then oozes from the fissures. Damaged bark provides an entry point for the disease, so be extra careful with whipper snippers and lawn mowers. Symptoms: The cankers can girdle a branch or the entire trunk, preventing water transport and leading to the sudden death of the affected limb, or whole tree. Keep an eye on the bark for cracking and resin. Early diagnosis can prevent dieback. Treatment: Large trees need to be injected with a fungicide. Phosphonic acid is used, diluted according to the instructions which accompany the product. This can be purchased as Fos-Ject 200, Phosphite or Phosphonate. You will also need a spring-loaded injector. Drill a 2cm deep hole at an angle about 15cm above the ground. Place the injection in the hole and release the spring mechanism. After treatment seal
