What do you do when a plant is not looking good in your landscape? Before you can effectively treat a sick plant the cause of the disease must be identified. Don’t be too quick to resort to pesticides. . .
The first steps in dealing with a sick plant are to determine what plant you have and what is causing the disease. Sometimes this is very easy to do, sometimes very difficult. The primary culprits include:
Water: Too much or too little water may cause plant disease. When a plant suffers or dies in a landscape, water is the most common culprit. Lasting damage may occur in a short time.
Soil: Soil with a low or high pH may cause disease in some plants. Compacted soil with poor aeration may also cause plant disease.
Nutrients: Deficiencies or toxicities of nutrients may cause plant disease.
Pests: Many animals and insect may cause plant disease. Do not assume that every insect you find on a sick plant is contributing to the disease; most insects are beneficial or neutral to your plant.
Pathogens: Fungi, bacteria, and viruses may cause plant disease. Pathogens may be identified by their appearance or by symptoms they incite in the plant.
Plant disease is always part of a complex. Numerous factors combine to cause a decline in plant health. It is important to understand the factors involved in plant disease to determine the best treatment.
To identify why your plant is sick you can use a variety of resources. Many reference books and pamphlets have been written about common plant diseases. State Cooperative Extension services have many excellent information sheets available on the internet. Asking an expert is also an option.
At Behmerwald Nursery we practice integrated pest management (IPM). The goal of IPM is to control pests and diseases in an environmentally and economically responsible fashion. In most cases an effective non-toxic response is available. Examples include removing spider mites with a stream of water, treating aphids with insecticidal soap, and improving soil drainage to alleviate root rot.
A word of caution regarding pesticides: Many unsafe chemicals were readily available to home gardeners in the past. Pesticides are designed to kill living things; some are more selective in their targets than others. If you have old, unused pesticides check to make sure they are legal to use. The National Pesticide Information Center is a good resource. To dispose of pesticides and pesticide containers, check earth911com .to find a recycling center near you.
Sources: This sheet has been compiled from experience and information from the EPA. To read more about IPM see IPM Principles (EPA).