Yew Problems

Wet Feet

• The condition known as “wet feet” feet occurs when the yew's roots become drenched in excessive moisture and start to die. Overwatering and a fungus that thrives in wet soil can induce wet feet, but the most common cause is poorly drained soil. Avoid planting on poorly drained sites if possible. Move any established plants on soggy sites to an area with better drainage. If you must use a location that retains moisture, plant the yew on a mound of soil that reaches the lower branches.

Insects

• Although yews have fewer insect problems than many plants, one particular pest, the taxus weevil, presents a dangerous threat. The insect first appears as a white grub that targets the roots and grows into an adult beetle that eats the foliage. The adult weevil rarely causes extensive damage to the plant, but the grub's feeding on the roots can lead to significant injury. Planting resistant varieties and using good cultural methods helps to mitigate the potential for taxus weevil infestations. In cases of large outbreaks, you may need to apply a pesticide. Common plant pests such as mealybugs and aphids occasionally invade yews as well. Introducing natural predators or using appropriate insecticides usually contains any significant invasions.

Shoestring

• Yews planted on sites where oaks or apple trees grew previously might become vulnerable to a disease caused shoestring root rot. Caused by a fungus, the rot creates black, root-like structures that look like shoestrings. Unlike roots, however, they have the same width for their entire length. They often join together where they cross. Inspect the root system of any plant you suspect has developed the disease. Discard any yews with shoestrings.

Wounds

• The branches of yews have a high vulnerability to wounds. For example, a branch that loses 1/3 of the circumference of its bark at a particular spot might dieback all the way to the tip, according to West Virginia University. Snow and ice can injure yews when they drop from nearby roofs. Always remove any tags held by wires from purchased plants. The wire can girdle, or encircle, the bark, causing serious damage.

Salt

• Yews face a threat from humans when planted near streets and sidewalks. The deicing salts some municipalities place on roads and walkways can cause yews to turn brown. Symptoms of salt injury tend to appear in spring, with plants closest to the area salted usually showing the browning first. Leaching the salt out of the soil with water might help affected plants.