How to Save An Evergreen Tree from Dying

The year-round beauty of an evergreen tree makes it a common landscaping choice. The elegance of the evergreen tree, coupled with the much-needed burst of green color during the winter, is a winning combination.  Because the tree stands out so much, when its’ leaves turn brown or start to fall off, it becomes a very noticeable blemish on the landscape. Find out how to save an evergreen tree from dying.

The majority of pests, diseases, and weather-related traumas an evergreen tree experiences can be overcome if caught and treated early. If it is allowed to progress too far, there is often little that can be done besides remove the tree. This is because evergreen shrubs or trees aren’t as equipped to regenerate with new foliage every year, like deciduous trees. Brown needles stay brown and dropped needles take a long time to renew.

To determine the best treatment for your sick tree, first, you need to figure out what is actually going on. There are several causes of brown or dropping needles, which range from dehydration to pests, to disease.

Most Popular Evergreen Trees

Why Are My Evergreen Trees Dying?

Water deficiency pictured on a Thuja Green Giant

Water Deficiency

Dehydration often happens in winter, or early spring due to lack of water.

Symptoms are yellowing or brown, droopy needles, and needle drop. In cold regions, the ground freezes, restricting water from reaching the tree roots giving way to winter injury. Critical moisture is lost through the needles, causing them to turn brown as they dehydrate. In the moment of freezing temperatures, it isn’t fixable. However, once the ground thaws, give the tree plenty of water.

In the future, water the tree thoroughly before the ground freezes. Also, lay a 3-4″ layer of mulch around the base of the tree to improve soil temperature and moisture retention. This will help protect the tree all year long.

Droughts also cause water deficiencies. During these times, water the tree deeply at least once a week. It is especially important to keep the tree adequately hydrated during times of drought because the tree is weakened and susceptible to contracting diseases and pests.

It is always best to water an evergreen tree once a week, deep and thoroughly. Frequent, light watering promotes shallow root growth, which furthers dehydration problems. Water-stressed trees turn brown from the top down and outside in.

Once the tree’s root systems are established it will not need watering as frequently.
Needle Cast disease pictured on a Ponderosa Pine tree | Photo by U.S. Department of Agriculture

Needle Cast Disease

The symptoms of this disease include brown needles, dramatic needle drop, and dying branches. This disease is highly contagious, and if not treated promptly, it will spread to other trees nearby.

Needlecast disease is treated first by removing all infected branches and foliage. Burn the debris or remove it far from the property. Never put it in the compost! Finally, apply a fungicide to the tree.

Rust Disease

If you see rust-colored powder on the needles and brightly colored swollen spots on the branches, your evergreen is suffering from rust tree disease. This is caused by a fungus that infects the leaves, causing blisters that burst and spread. Remove all the infected leaves and branches and treat the tree with a fungicide. Tree care is especially important when they are young trees to ensure a long healthy life. It is important to break the life cycle of the disease.

If this fungal disease is common in your area you can choose rust resistant trees
Douglas Fir experiencing root rot | Photo by Oregon Department of Forestry

Evergreen Tree Root Rot

A disease caused by a fungus, evergreen root rot will kill a tree if not dealt with quickly. The symptoms of root rot include wilted and discolored needles, blisters alongside the roots, and soft, weak wood beneath the bark. The only way to treat root rot is to dig away all the damp soil around the roots and let it dry.

Root rot is caused by too much water at the roots or from the soil moisture being too wet. Pick your planting site wisely as this can determine the life of your evergreen tree. Planting in a site with well drained soil is essential for the health and safety of the tree.
Mountain pine beetle devastation in the greater Yellowstone ecosystem

Pine Beetles

These troublesome pests suck the sap out of the branches from the inside. They leave small holes surrounded by rust-colored powder and holes dripping yellow sap. Pine beetles generally only attack weak trees, so if your trees are healthy, they should be safe. The best defense against pine beetles is defense. Prune any dead or diseased branches off the tree, remove any debris around the base that could attract plant diseases, and keep it well watered.

If you know there are pine beetles attacking trees in your area, apply insecticide to the tree preemptively. Trees that are insect infested with pine beetles often have to be removed.

Lack of Sun

Evergreen trees need lots of full sunlight. Sometimes, the lower branches turn brown because the higher branches are blocking the sun. Other times, the tree is not planted in a sunny enough location. If the issue is the upper branches blocking the sun, a careful pruning helps light penetrate through to the lower limbs. A tree planted in a shady location should be relocated, if possible. Plant future evergreens in full sun areas.

We hope this blog helped you figure out why your evergreen trees are dying. Have you fixed a dying evergreen tree and brought it back to life? Share your experiences with us in the comments. Let’s help each other grow!

Other blog posts you may like are the Grow Guide for Evergreen Trees, Grow Guide for Thuja Green Giant, & Evergreens in the Winter Landscape.