How to Treat Diseased Hemlock Trees

Pruning diseased trees can help keep them healthy.

Hemlock trees are evergreen trees that are grown as decorative garden or landscaping plants. Caring for hemlock trees requires attention to diseases, as well as prevention and cures. Gardeners can recognize signs of disease problems by examining the branches of the hemlock trees; for example, wilting, dying or dead branches can all be signs of a diseased tree. Treating a diseased hemlock tree can help restore it to health and ensure that it continues growing for many years.

Things You'll Need

• Pruning shears
• Wood alcohol
• Shovel
• Pesticides
• Fungicides

Instructions

1. Check the hemlock tree for signs of disease, including patches of fungus, dead or wilting limbs, insect larvae or damaged bark.

2. Examine the visible roots of the tree for signs of disease, including white or blackened roots, dead roots or fungus growing at the base of the tree.

3. Use pruning shears to prune dead, sick or wilting branches from the hemlock tree. Sanitize the pruning shears with wood alcohol before and after pruning each branch to prevent the spread of disease to other portions of the tree.

4. Prune branches at the nearest adjoining branch or at the trunk of the hemlock tree. Make cuts at a 45-degree angle to help the branches heal and promote the growth of new, healthy branches.

5. Irrigate the soil around the base of the hemlock tree to aid in draining excess water away from the tree. Excess water can provide a place for fungus to grow, which can lead to diseases of the hemlock tree.

6. Apply a pesticide to the tree if the diseases are caused by insects. Follow all directions on the package for the best results. Apply a fungicide to the hemlock if the disease is fungal, and follow all directions for application.

7. Continue pruning and irrigating the hemlock tree while it is ill. Add pesticides or fungicides as necessary to control the disease.

References

• Northeastern Area State and Prviate Forestry: How to Identify and Manage Pine Wilt Disease and Treat Wood Products Infested by the Pinewood Nematodes
• Ohioline: Evergreen Trees for Ohio
• University of Illinois Extension: Selecting Trees for Your Home
• University of Maine Extension: Maine Tree Species Fact Sheet

Resources

• Washington State University: Propagating Deciduous and Evergreen Shrubs, Trees and Vines
• University of Tennessee Extension: Hemlock Wooly Adelgid