Plant Diseases

Plants that acclimate easily to a new environment are stronger and less prone to disease than plants that struggle to adapt.

Appropriate gardening practices, such as composting and other organic methods, add to the plant's natural abilities.

But even under the best of conditions, plants can develop diseases. And there are numerous diseases that can attack plants.

Identifying the causes and symptoms of some common diseases makes it possible for us to treat our plants effectively.

Bacteria, fungi, viruses or nematodes cause plant diseases. Since many diseases respond to the same treatment, exact identification, which can be difficult, is not always necessary.

County Extension Offices can often assist with identification and treatment information if you provide a sample of the infected plant.

Causes of Plant Diseases

Molds can appear as gray powder or fur on fruits and flower buds. Peonies, tulips and many fruits are affected by mold.

Remove spent blooms and provide good air circulation to help prevent it. Treat with a product specific to the plant.

Mildew appears as a powdery substance on leaves, flowers and fruit.

Buds will tend to shrivel up, fruit becomes misshapen during growth and leaves become distorted.

Melons, cucumbers and phlox are prone to mildew problems. Fruit may develop prematurely on trees and be poor in flavor.

Prune or stake trees to provide better circulation and treat with sulfur weekly.

Nematodes attack the roots of most vegetables and ornamentals.

Roots will be swollen, leaves will have areas of dead tissue, and the plant's growth will be stunted. Wilting and overall unhealthy appearance is common.

Plant marigolds between your crops to repel the nematodes, and rotate crops every year as a preventive measure. Use of good organic composting material also helps repel these pests.

Viruses cause plants to grow slowly and have small harvests. Leaves appear cupped or curled, with streaks or spots.

Burn any plant suspected of carrying a virus to prevent spreading, and control the insects that spread it.

By planning your garden in a way that utilizes the natural environment to best advantages and preparing the site using organic methods, we greatly reduce the risk of diseases attacking.

With routine maintenance and care we can limit the damage done by plant diseases and further prevent their spread.

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