tar stain disease - plant disease and pest image - cropped

Healthy Trees

Diagnosing tree health problems can be complicated. Preventing tree damage and death starts with knowledge. By exploring these common tree health problems, you’ll start to see how you can help. Planting it right and caring for it in ways that avoid these problems goes a long way. If you’re already experiencing problems, these might help you identify the cause.

Buried Too Deep


Trees are often buried too deep during the construction phase of a building project. A common reason for the decline of mature trees, symptoms often include:

  • Reduced growth rate
  • Diminished leaf size or defoliation
  • Yellowing (often mistaken for poor soil nutrition)
  • Leaf mis-timing (Late emergence, early coloration)
  • Split bark

This condition can also increase a tree's susceptibility to borers and girdled roots. If left untreated, the tree will usually experience branch dieback and an eventual premature death.

Girdling of the Roots

Often seen when trees have been planted too deeply or have soil obstructions preventing normal root growth. This condition also arises if container-grown trees remain in the container too long, or planting holes are too narrow.

When compacted soils or soil obstructions prevent normal root growth patterns, the roots tend to clump or even encircle the tree. In the case of trees planted too deep, the root systems tend to grow upwards and will struggle to get the same level of oxygen and water that would be available at the optimal depth.

Twine Strangulation

A popular way to deliver and plant trees is to contain the root ball in burlap, twined around the bottom of the trunk. While this can lead to healthier outcomes than container-grown equivalents, there are health concerns.

 

When planting trees, insist that twine is removed - and burlap should be slashed or removed to facilitate root establishment.

While this is a problem easiest remedied at planting, it's something our trained staff can diagnose and provide relief for your strangled trees.

Overgrown

Image Credit: Joseph OBrien, USDA Forest Service, Bugwood.org
Most landscaped trees need pruning every couple of years. It's important to remove dead branches, train young trees for proper structure, and promote airflow.

Other reasons regular pruning is important

  • Storm resilience
  • Preventing the spread of insects and diseases
  • Maintain your view and clearance for structures and pathways
  • Enhancing the shape

Regular pruning is a healthful activity for fruit-producing and ornamental plants alike. In mature shrubs, pruning can help rejuvenate growth.

Professional pruning accounts for factors like structural integrity, aesthetics, and overall plant health.

Irrigation & Drainage

Edema. Image Credit: Cheryl Kaiser, University of Kentucky, Bugwood.org

Plant stress can be caused by both too little water and too much water though overwatering is more common.

Seedlings and new transplants are more sensitive to excess water conditions than more established plants. Likewise, deciduous plants are less sensitive to waterlogged soils than evergreens.

Soil composition plays a large role in the balance of water retention and drainage. Heavy concentrations on clay can hold too much water.

Irrigation and drainage issues present in leaf wilt and discoloration, root rot, and even physical bulges (edema) caused by too much water at a cellular level. Similarly, stem swelling may occur.

Winter Injury

Image Credit: Dave Powell, USDA Forest Service (retired), Bugwood.org

While it's commonly believed that an unusually cold winter is the cause of winter injuries, the causes are more varied - as are the manifested effects.

Low-temperature injuries are more commonly associated with temperature fluctuations than the cold temps alone. It's the sudden, hard freeze.

Low temperatures do affect many plants, especially those living on the edge of their viable USDA zones. One of the most common damages associated with low temperatures is root damage, especially in shallow-rooted species.

During very cold winters can cause vascular damage even in hardy specimens. This is indicated by bud break and shoot expansion, followed by sudden wilting. New growth is often more susceptible to damage than older growth.

Northern Michigan ice storms and heavy sudden snowfalls are notorious for causing physical breaks on branches - especially those that haven't been properly pruned.

Young trees are particularly susceptible to girdling by small animals like mice and rabbits. Indeed, this is a common type of winter injury that may remain unnoticed for some time.

Many forms of winter injury are commonly confused as a form of needle cast or blight.

De-Icing Salt Damage

Image Credit: Joseph LaForest, University of Georgia, Bugwood.org

Evidence of salt damage presents first on evergreens, later during spring for deciduous trees. Some of the warning signs include:

  • Leaf burn/discoloring around the edges (browning needles at tips for evergreens)
  • Damage/discoloration limited to the side facing sidewalks, roads, and driveways
  • Decreased foliage, flower or fruit stunting and delay
  • Bud damage or death
  • Reduced vigor, discolored foliage, premature fall colors

Look for trees that are highly susceptible to salt damage; maples, dogwood and boxwood, walnut, white pine, and hemlock.

The remedy for salt damaged plants varies based on the extent of salinization present. While there are things we can do to help you, an ounce of prevention is worth a pound of treatment.

Different salts can make a difference. For example, Calcium chloride is more expensive though generally easier on vegetation. Sand is still more gentle. Having a directional spreader helps keep the de-icing agent on the walking or driving surface where it belongs - though water runoff can still introduce it to soil and roots.

Some professionals will recommend spreading gypsum (a component in drywall) as a preventative measure to shield roots.
Finally, planning and placement of plants can help to limit their exposure.

Careless Pesticide & Herbicide Applications

Image Credit: Joseph OBrien, USDA Forest Service, Bugwood.org

Pesticide and herbicide problems are very common where turf, woody shrubs and ornamentals intersect.

Numerous herbicides act as plant hormones that cause deviation from normal growth processes.

Unintended direct contact from direct spray or vapor drift is a common source of careless pesticide and herbicide application. Additionally, root absorption from treatments leached into soil or shared root zones contribute greatly to this misapplication. That's why whenever possible we utilize our Arborjet system to deliver treatments only to intended plants.

When traditional application methods are required, careful application is required.

Some symptoms of misapplied pesticides for broadleaf/deciduous species include scorching, leaf cupping, necrotic spotting, decline, and dieback.

In conifers/evergreens, look for needle browning and dropping, bud death, and twisted/abnormal structure.

Avoid using products that boast "extended control" formulas especially those that contain imazapyr. This non-selective herbicide is absorbed into leaves and roots, moving rapidly. As a water-based chemical, it can seep into other areas it was not applied.

We've found numerous dead trees because of these extended control formulas like Roundup 365, Ortho Groundclear, and Roundup Extended control. Homeowners spray mulch rings to control weeds and inadvertently kill the tree.

Diseases & Pests

Hemlock Woolly Adelgid
Image Credit: Chris Evans, University of Illinois, Bugwood.org

We're actively involved in identifying and treating numerous pests and diseases that threaten northern Michigan plants.

Learn more about some of the many conditions we're both finding and actively looking for. Many conditions have overlapping symptoms and even secondary infections.

There are things you can look for, but sometimes it's best to call the experts.

See our Pests and Diseases page for more information

Compacted Soils

Image Credit: William M. Brown Jr., Bugwood.org

Ideal soil composition is about 50 percent solid matter and 50 percent pore space, leaving room for air and water.

Compacted soil can cause water runoff, thus dehydration. It prohibits roots from getting enough nutrients as well as oxygen. Trees exhibit slow growth both in the number and size of leaves and fail to thrive.

Branches will die back and the trees will become susceptible to secondary pest infections and environmental stresses.

While some mild or moderate treatment is possible using biological methods like mulch and earthworms, sever compaction (complicated by soil composition) requires more than soil amendment or mulching.

Compacted soils are quickly and safely remedied using the forced air of an Air Spade tool. While conventional digging damages roots, this technique opens up new ways to fix compacted soils.

 

Expert Help

The best way to keep your trees healthy is to catch conditions early. Regular inspection is a key component of our Plant Health Care services.

As experts in identifying tree health conditions, we’re also experts in solving them. If you’ve spotted what might be on of the above conditions, we can help you confirm and remedy the problem – promoting the long-term health of your trees.