Guide for Beautiful and Healthy Trees

The Real Cause of Many Tree Problems

Washington, D.C. – Insects and microorganisms are not the real cause or starting point of many tree problems. These organisms are often secondary agents that attract weakened, wounded, improperly treated, neglected, and generally unhealthy trees.

Poor tree health is a major worldwide problem. Fighting the secondary agents that are often very obvious, or the symptoms of poor health, will not solve the basic problem.

Here are some brief guidelines for you, the homeowner, that will help you keep your trees beautiful, safe, and healthy.

Give Trees a Good Start

Plant the right tree in the right place

• Do not plant pin oaks in alkaline soils
• Do not plant trees in old alkaline building rubble
• Do not plant willows in dry soils, pines in wet soils
• Do not plant birches in shade, dogwoods in unprotected open sites
• Learn the biological requirements of your trees
• Do not plant unless you plan to maintain

Plant Properly

• Do not crowd trees in small holes with compacted soil
• Do not over-amend the soil with humus
• Do not fertilize at planting time
• Do prune dead and dying branches and roots

Keep Grass Away

• Do not water grass heavily near trees that normally grow on dry sites
• Do not lime grass heavily near trees that grow best in acid soils
• Do not wound trees with lawnmowers and other machines
• Heavy use of herbicides may harm trees.

• Do not tie young trees so tightly that they do not move
• Do not leave braces on after tree is established
• Do not kill bark with cords, wires, bands, etc.

Prevent wounds

• Do not allow anyone to climb your tree with spikes
• Do not allow heavy construction machines near your tree
• Do not park cars near trees

Wound Dressings

Wound dressings do not stop rot

• Do not apply house paints or wood preservatives
• Do not apply heavy coats of any material

Research shows that wound dressings do not stop decay or stall rot. Trees have been responding effectively to their wounds for over 200 million years. Do not interfere with this natural process. Keep your tree healthy and it will take care of its wounds. In a short time the wound surface will blend perfectly with the tree bark.

Tree Treatments

Treat wounds
If trees are wounded, remove injured bark with a sharp knife. Make cuts as shallow as possible. Forming an elongated ellipse is not necessary. Make all margins rounded; do not point tips. Do not enlarge the wound. Do not paint. Do everything possible to maintain health – water, fertilize, prune.

Cavities
If cavities are to be filled, do not clean so thoroughly that the boundary between decayed wood and sound wood is broken. Fill with nonabrasive materials. Leave for professionals.

Injections and implants
If you plan to have chemicals injected or implanted in your trees, make certain that it is done only by highly skilled professionals. Check injection and implant holes after one season to make certain they are closed. Injection and implant holes should be very small and shallow at the tree base, not in the roots.

Cable and brace
If rot is present, put rods entirely through the stem, and use round or oval washers on both sides. Washers should be seated on the wood, not deep in the wood or on the bark. Cables should allow tree to move slightly. Leave to professionals.

Help Trees Stay Healthy

Before you fertilize or consider treatments for microelement problems, have a soil test done. Your tree may require soil acidification before fertilization, or treatment of microelement problems. Fertilizers add elements essential for healthy growth. Fertilizers are not tree food!

Trees get their energy from the sun. Leaves and needles trap energy in a molecule of sugar. Sugar is tree food. Keep leaves and needles healthy by timely treatments so trees can get their food. Keep soils free of compaction so roots can get water and essential elements. Do not over fertilize.

Some insects and microorganisms DO start tree problems. When in doubt about what to do, contact the extension agents from your county, state, or university, or ask the United States Forest Service or professional arborists.

Check for Potential Hazards

• Large dying and dead branches
• Rot in roots and base (fruit bodies of fungi are signs of rot)
• Large deep vertical cracks on opposite sides of trunk
• Be on the alert 5 to 10 years after construction. Have hazardous tree crowns reduced by professionals.

Prune Correctly

Correct pruning is the best thing you can do for your tree.

• Do not make flush cuts behind the branch bark ridge
• Do not leave living or dead stubs
• Do not injure or remove the branch collar
• Do not paint cuts

The best time to prune living branches is late in the dormant season or very early in spring before leaves form. Dead and dying branches can be pruned anytime. Use sharp tools! Make clean cuts. Be careful with all tools. Safety first!