Tree and Shrub Problems Not Caused by Disease or Insects (abiotic)

Winter damage on cherry laurel

Key Points

Tree and shrub problems, to a large degree, are not due to diseases or insects. They are often referred to as abiotic (Latin word meaning “without life”) causes.

It may take a long time for abiotic problems to cause symptoms or a problem and sometimes it can appear that a plant died very suddenly, even overnight. But, by the time one notices that a tree or shrub is dying, it is often too late to correct the problem. It is important to recognize these symptoms early and try to correct the adverse conditions causing them.

• Trees and Shrubs Slowly Decline
  
• Environmental (many are weather-related)
• Cultural (how plants are taken care of)
• Miscellaneous
• Key for Diagnosing Abiotic Plant Problems

General information about abiotic (not related to anything living) problems

• Diagnosing abiotic plant problems can be difficult because often multiple factors are involved and plants can have symptoms very similar to a disease or insect infestation.
  
  

• Determining the difference between the “symptom” and the “sign” of a problem is the first step in making a diagnosis. A “symptom” is an unnatural change in a plant’s appearance or growth caused by one or more factors. Example: wilting of leaves or early fall color. A “sign” is the actual presence of organisms such as insects, mites, or mushrooms. Examples: Insect droppings on leaves; the white coating on crepe myrtle leaves caused by the powdery mildew fungus.
  
  
  Symptoms of drought-stressed leaves (leaf curl and scorch)

  
  A sign of cottony camellia scale (white, waxy covering
  protecting eggs laid by the female scales)
  
  

• Insect or disease injury may also be evident but not severe enough to be the primary cause of a plant problem. But, a stressed plant in combination with a disease or insect is very problematic.
  
  
• Stressed plants are more susceptible to disease and insect problems. 
  
  
• Typical distress symptoms of an abiotic problem may include very slow growth, poor foliage color, scorch, sparse growth, branch die-back, or even death of the plant. 
  
  
• Careful site selection, proper planting, protecting trunks and roots from mechanical damage, watering during plant establishment, and during dry weather are some ways to protect plants from stress factors.
  
  
• It is important to recognize stress symptoms early to prevent further decline.
  
  

• Trees planted in natural areas and native soil have a much longer life-span than trees planted in a typical home or commercial landscape.

Trees and shrubs slowly dying  (decline)

Environmental (many are weather-related)

• Climate Change
• Excess Rain
• Heat and Drought Stress
• Winter Damage or Burn (freeze or frost damage)

Cultural (how plants are taken care of) and Site Conditions

• Excess Mulch
• Poor Care after Planting
• Planted too Deeply
• Poor Site
• Poorly Drained Soil
• Soil Compaction

Miscellaneous

• Broken Branches and Lower Trunk Damage
  
• Changes in Water Flow
• Construction Damage
• Deicing Salt/Fertilizer Damage
• Embedded Wires and Wire Baskets
• Girdling Roots
• Grade Changes
• Herbicide Damage
• Weak or Damaged Plants
• Root Damage
  

Adapted from publication HG 201 Homeowner Landscape Series: Common Cultural and Environmental Problems in Landscapes, Authors: Dave Clement, Ph.D., Principal Agent, University of Maryland Extension and Mary Kay Malinoski, Principal Agent, University of Maryland Extension. And publication HG 86 Common Abiotic Plant Problems, Author: Raymond Bosmans, Professor Emeritus University of Maryland.

Edited by Jon Traunfeld, HGIC Director and University of Maryland Extension Specialist. Complied by Debra Ricigliano, HGIC.

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