Diagnosing Shrub and Tree Problems
This is my site Written by Geoff on January 1, 2003 – 7:30 pm

We often receive calls asking for advice or help with a sick tree or shrub. Usually the questions are hard to answer over the telephone, without seeing the tree, but not always. Two of the most common questions are; “Why did the leaves on my Amur Maple turn bright red and fall off when it is only Summer?” or “My White Pine’s needles turned brown this Winter when does it turn green again?”. 

The answer to both these questions are, unfortunately, never as these trees are dead. Nothing can be done to save them and costly replacements will be required. If only the homeowner had taken the time to inspect his trees and shrubs in time correct to the problem, these trees may have been alive today. 

Of course, not all tree problems can be solved easily, just ask the American Elm or Chestnut, if you can find one. Catching a plant problem in the early stage, at least gives you a chance. It also gives you an opportunity not to make the same mistake twice, such as planting too deep or in the wrong location. Who knows, you might even be able to save a tree or two by your quick action. 

If you are like me, you overlook your trees and shrubs in the Spring and Summer, when everything else is in bloom. I have to make it a point to inspect each tree and shrub. You need to do the same, it only takes a few minutes. 

The Colorado State University has but together a list of the most common symptoms and theircauses which you can use as a quick reference. 

  1. Symptoms: Poor foliage color, stunted weak growth, gradual decline.
    1. Planting too deeply or too shallow.
    2. Poor drainage; plants located near down spouts, in low areas, in non-drained planter boxes, and in beds over very compacted soil.
    3. Damage to stem or trunk
      1. Freeze damage.
      2. Bark splitting caused by sudden freeze following periods of mild weather. Symptoms may not show until summer time.
      3. Mechanical damage such as, lawn mower or other equipment can skin or girdle bark or borer damage occurring when these insects gain entrance into the stem and destroy tissue just under the bark.
    4. Poor soil preparation, heavy soils that are easily packed and very sandy soils produce poor growth.
    5. Soils too acid or too alkaline.
    6. Drought damage, usually occurs on plants in light sandy soils, under overhanging roofs, or in planter boxes.
    7. Nematode damage, microscopic work-like organisms attack root system and interfere with ability of roots to take up water and nutrients.
    8. Needs proper fertilizer.
    9. Competition from other trees, trees and shrubs often compete with other plants for water, light, and nutrients.
    10. Pot bound root system, roots were not altered as needed at planting.
  2. Symptoms: Shrubs die suddenly.
    1. Too much fertilizer kills roots and top cannot get needed water. Damage more likely to occur during dry periods.
    2. Root rots caused by fungi or bacteria.
    3. Insects, borers and beetles that attack trunk can cause sudden damage.
    4. Severe drought with new plants and shallow-rooted plants most susceptible.
    5. Leakage from underground gas lines.
    6. Weed killer damage when applied incorrectly.
  3. Symptoms: Yellowing foliage.
    1. Insects small sucking insects.
    2. Poorly drained soil.
    3. Too much fertilizer.
    4. Needs proper fertilizer.
    5. Soils too acid or too alkaline.
    6. Nematode damage.
    7. Damage to stem or trunk.
    8. Poor soil preparation.
    9. Roots disturbed by cultivation, roots of shallow-rooted plants are easily damaged by cultivation.
    10. Construction, damage from nearby grading or construction often result in damage to roots or soil filled over roots.
    11. Pot bound root system.
  4. Symptoms: Leaf drop in spring.
    1. Natural occurrence, older leaves fall as new leaves develop.
    2. Unusually wet or dry conditions, trees shed leaves to deal with stress.
  5. Symptoms: Failure to flower.
    1. Shrubs or trees are too young, age and a slowdown in growth rate will increase flowering.
    2. Too much vegetative growth because of overfeeding.
    3. Pruned at the wrong time, prune spring flowering shrubs after blooming and summer flowering shrubs in fall and winter.
    4. Too much shade.
  6. Symptoms: Failure to produce berries.
    1. Cold or frost during flowering; kills developing fruit.
    2. Female plant with no male friend around or only male plants
    3. Improper pruning, often berries are produced on older growth.
  7. Symptoms: Occasional branches die.
    1. Stem breakage, shrubs such as dwarf holly have brittle limbs, easily broken by animals or children.
    2. Disease.
    3. Insects.
  8. Symptoms: Browning of leaf tips and edges and leaf spotting.
    1. Drought.
    2. Cold damage, exposure to bright light and strong winds during low temperatures. Spots develop when ice accumulated on foliage in sun. Injury also occurs during prolonged periods of freezing temperatures.
    3. Poor drainage.
    4. Root loss due to recent transplanting.
    5. Too much fertilizer.
    6. Root rot diseases.
    7. Damage to stem or trunk.

Many problems found can be corrected by the homeowner. While not easy, trees can be moved, drainage improved, and Winter protection can be provided. The homeowner can also learn proper pruning techniques, fertilization methods, and to be more careful mowing and trimming. We recommend, for large tree damage, insect, or disease problems, the owner call in a professional arborist. One can quickly be located by going to the National Arborists Association’s web site and typing in your zip code. For example, in our area, when you type in 49120 it tells youWatson’s Tree Service is the one to call.

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Modified: March 7, 2009 at 7:32 pm UTC

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