Evergreen trees tend to be tough, adaptable, and easy to grow, which is why we are always shocked and saddened to find them turning brown and even dying. There are many reasons for evergreen foliage to turn brown. Sometimes this symptom is deadly and other times it is simply a minor side effect of the environment. Most of the time keeping your tree healthy can prevent the browning of evergreens.
Did you know evergreen trees drop their foliage just like deciduous trees? Well, they do. They just do it gradually overtime throughout the year. Older foliage dies and is replaced by fresh new foliage. Natural browning is generally going to be seen peppered throughout the tree and often more so in the inner portions of the tree where there is less light. This type of browning is normal, natural, and healthy!
This is the most obvious reason for evergreen trees to turn brown. The foliage will turn brown evenly, often from the bottom up. You will notice brittle or dry foliage that starts to shed once the problem is severe. If you notice your evergreen trees turning brown, start with water. It is pretty hard to overwater a tree if your water correctly.
- For newly planted trees (less than 3 months) water deeply a few times per week despite the rain (unless you are getting a lot).
- For established trees water deeply once or twice per week when there is little to no rain.
Too Much Water
Too much water can cause root rot. Generally, this only happens during a very rainy season or when evergreen trees are planted in a wet site that doesn’t drain well or is not planted properly. This is why planting in heavy clay can be a problem. It can create a bowl that traps water. Planting too deep also causes root rot and other problems for trees.
Tips to Avoid Root Rot
- For heavy clay soils amend your soil below where the root ball will sit. Add compost and some potting soil, but never more than 50%. Your tree will have to acclimate to your existing soil. Sometimes just breaking up or tilling clay soil can make all the difference to help a new tree get started.
- When planting a tree, the top of the root ball should always be slightly above the existing soil line for best results.
Treating Root Rot
- The wet soil must be removed around the roots to allow the roots to dry.
- If your tree is planted too deep and dying, replanting may be your only option. Remove your tree as gently as possible and keeping as many roots intact as possible and add soil to the bottom of the hole so your tree will sit higher in the hole.
Browzing can be seen on many evergreens. Most trees green-up in spring. But bronzing can be an early sign that your tree needs some help in winter. It occurs when your tree is dehydrated from drought, wind, and sun. Anti-desiccants can help your evergreen tree’s foliage retain moisture. But I don’t find these products to be practical in most cases. A deep watering once weekly can help your tree immensely, but if the ground is frozen the water may not penetrate well.
Tips to Avoid Winter Browning
- Water deeply prior to each heavy freeze, especially before the first hard freeze of the year.
- Apply a thick layer of mulch at the end of the fall or prior to the first hard freeze.
- You can wrap the trunk or your tree in burlap or netting, but I don’t particularly find this method practical unless you have one small tree that is just your baby. If that is the case, go for it! Otherwise, water, mulch, and go get some hot cocoa.
Fungal diseases like canker, blight, and rust can be a problem for evergreen trees. Symptoms include browning or foliage discoloration from the top-down, cankers (sunken dead patches) that may ooze, powdery orange, red, or yellow spores on the leaves or needles, and leaf or needle drop. If you suspect disease your best bet is to remove the affected branches, dispose of them immediately, and disinfect your pruning equipment, or contact a professional arborist.
Pine bark beetles, bagworms, spider mites, and other pests can cause browning in evergreens. Other symptoms include small holes in the trunk and large branches and sawdust, bags coated in dead foliage about 2 inches in length hanging from branches, and yellow speckling on needles. Treat mites with horticultural oil, insecticidal soap, or spinosad. Treat bagworms with Bacillus thuringiensis, spinosad, permethrin, carbaryl, or malathion. If you suspect pine bark beetles contact a professional.
Tips to Keep Your Evergreen Trees Healthy!
According to plantingtree.com, the key to keeping your evergreen trees green is keeping them healthy.
- If conditions are dry, give them a drink. YES, even drought-tolerant trees like evergreens enjoy a deep watering on occasion!
- If your soil is nutrient weak, give them some food.
- Give your trees as much space as you can for good air circulation.
- Avoid overhead watering for trees that are susceptible to disease.
- Look for evergreens that are disease and/or pest resistant.
- Talk to your local extension agent to find out what evergreen trees they recommend for your area and which to avoid.