Diagnosing Plant Symptoms and Problems

When plants and trees show signs of damage, distress or disease it’s often overwhelming to determine what’s wrong. Is the plant suffering from environmental stress or disease? Is it being attacked by insects or is it damaged from chemical misuse? With the number of things that can go wrong with plants, it can be difficult to know where to begin to look for answers. By determining the answers to a few key questions, gardeners can narrow the focus and more easily discover what ails their plants.

Basic Information for Diagnosing Plant Symptoms

When diagnosing plant symptoms, the first place to start is with the very basic information.

• What kind of plant is it? What cultivar? Often plant diseases are host specific. Also, certain plant species need specific environmental conditions.
• When was the plant planted? Improper planting and transplant shock are common reasons for plant stress and decline.
• Are other plants in the area affected? Are they the same species? Plants of different species in the same area showing similar symptoms indicates an environmental issue such as drought, overwatering, soil problems or chemical misuse.
• Where is the plant planted? Plants planted in unsuitable locations in regards to things like sunlight or drainage will show signs of stress.
• How do you water the plants? Plants are commonly watered too much or too little and will show signs of decline if either of these two extremes are true.

Plant Symptoms Indicating Disease or Insects

If it’s been determined from the basic information that a plant’s decline is not related to environmental issues, gardeners must analyze other symptoms.

• What part of the plant is showing symptoms? Leaves, stems and roots can all show signs of disease. Which part of the plant is affected will further narrow down the number of possible diseases the plant is suffering from.
• Are there signs of fungus on the plants? Fungus often shows up as a gray, white or black powdery substance on leaves. Gardeners may notice puffs of dusty material coming off the leaves when they are disturbed. These are fungal spores.
• Are there signs of insects? Beside the insects themselves, there may be excretions in the form of black or brown spots (not related to leaf necrosis or dead spots) or honeydew. Insects may also eat and destroy leaves and shoots.

Once armed with this basic information, gardeners can either conduct an Internet search or present the information to a garden professional to determine the cause of a plant’s decline. Generally, diagnosing the cause of a plant decline is a simple process of elimination. Starting with the simplest information and eliminating possible causes one by one makes solving plant problems fairly easy.