Garden Problems

When we think of garden problems, what most often comes to mind are the insects that seem to enjoy our flowers and fruits as much (or more) than we do. However, there are a whole range of problems and pests which can turn your pleasurable gardening experience into a nightmare:

• Cultural Problems:
  These are plant problems caused by climatic, environmental, pollution, and human factors. Examples are cold and wind injury, drought or over watering, poor pollination, hail, planting mistakes, and improper plant selection for the site. Surprisingly, most plant problems seem to be related to cultural issues.
  
  
• Plant Diseases:
  Plant problems primarily caused by microscopic bacteria, fungi, and viruses. These diseases may attack the foliage, stems or trunks, roots, or all of the plant. Common plant diseases are crown galls, root rots, powdery mildew, verticillium wilt, and rusts.
  
  
• Insects and Invertebrates:
  These are plant problems caused by the activities of insects, mites, and other small invertebrates. The damage may be caused by the adult or juvenile form of the creature, and all or only a portion of the plant may be attacked. Common examples are aphids, fall webworm, oystershell scale, leafrollers, spider mites, and slugs. One must remember that many insects are beneficial predators of harmful insects, and should be encouraged and protected.
  
  
• Chemical Damage:
  This occurs when chemicals (usually herbicides) come into contact with and damages a desirable plant, either from overspray and/or drifting of the product, contaminated water runoff, clothes or tool contamination, improper application or product selection, or soil contamination. In some cases chemical damage to plants may resemble damage cause by cultural problems, but is often more localized in scope. In addition to herbicides, some insecticides and fertilizers, when used improperly or in the wrong location, may also harm plants. "The Label is the Law" when it comes to pesticide use. Remember that you must read and follow pesticide labels exactly!
  
  
• Soil Problems:
  Although our local soils are generally rich and fertile, situations may occur where the source of your plant problem is the soil itself. Examples of soil problems may be acidic soils (very common in our area), various nutrient deficiencies, poor soil structure due to composition or improper tillage, and soil compaction due to vehicle and foot traffic. It is recommended that you have your soil tested by a laboratory to identify any potential or actual problems.
  
  
• Animal Problems:
  Large animals may cause extensive damage to a garden: deer browse on plants, sapsuckers bore holes in trees, mice girdle stems, moles tunnel under lawns, and birds take fruit. Methods of control include live trapping, netting, repellants, fencing, and planting unpalatable or resistant plants.

Integrated Pest Management

When you have a garden problem, especially one involving insects or a disease, the temptation is to grab a sprayer full of pesticide and start spraying. However, research and experience has shown that this is may not be the best approach, and may actually cause additional harm by killing beneficial insects and contaminating your garden and the environment. A much better approach is called Integrated Pest Management.

Integrated Pest Management (IPM) is an environmentally sensitive approach to controlling pests that does not rely totally on pesticides. IPM depends on frequent monitoring of plants or structures and the accurate diagnosis of the pests so that control strategies are used only when and where needed. A variety of control methods - cultural, mechanical, biological, and chemical - may be employed. IPM takes a look at the entire system and thus monitors the entire system, not singling out only one pest problem.

An excellent article on IPM, prepared by WSU Puyallup, may be found here.

When you have a plant problem, you must first identify the exact cause before you can decide on a course of action. There are several which must be taken to accurately diagnose the cause of a garden problem:

1. Identify the plant and learn its normal growth characteristics.
2. Carefully examine the affected plant and other plants in the landscape.
3. Look for patterns of damage on the plant, and throughout the landscape.
4. Note the symptoms of the problem, such as chlorosis or leaf spots.
5. Identify the exact cause, considering all information you have found.
6. Use the principles of IPM to identify the least environmentally-damaging solution for your problem.

Resources

There are far too many potential garden pests, diseases, and cultural problems to list individually in this section. However, WSU Extension has put together several excellent online references to assist you in identifying and correcting garden and general pest problems:

• Hortsense. Provides home gardener fact sheets for managing plant problems with IPM, along with information on cultural controls and Washington-registered pesticides.
• Pestsense. Provides home gardener fact sheets for managing common indoor pest problems with IPM, along with information on cultural controls and Washington-registered pesticides.
• Urban IPM. The WSU Urban IPM and Pesticide Safety Education Program. Provides education with an emphasis on personal safety, environmental protection, and effective integrated pest management.

WSU Extension Library. Provides links to various articles and sites dealing with plant problems.

Plant & Insect Diagnostic Laboratory, WSU Puyallup Research and Extension Center:

• Plant Disease and Insect Identification Pests Leaflet Series. The PLS covers insect problems, diseases, abiotic problems, and other miscellaneous situations.
• Frequently Asked Questions About Plant Problems.

Internet Center for Wildlife Damage Management. The Internet Center for Wildlife Damage Management is a non-profit, grant funded site that provides research-based information on how to responsibly handle wildlife damage problems.

Arthropod Pests of Stored Foods. University of Nebraska, Department of Entomology. Images of insect and mite pests.

PNW Insect Management Handbook. Oregon State University. Information on insect pests, including photographs and control suggestions.

Biological Control: A guide to Natural Enemies in North America. Cornell University. This guide provides photographs and descriptions of biological control (or biocontrol) agents of insect, disease and weed pests in North America. It is also a tutorial on the concept and practice of biological control and integrated pest management (IPM).