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Fighting Plant Diseases in the Garden

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Simply put, strong, healthy plants are less susceptible to disease. To keep your plants healthy, one must take care of the basics first. It makes everything easier down the line. And you know what they say, “An ounce of prevention. . .”


The basics include:  

  1. Provide sufficient light, good soil, adequate moisture 

  2. Employ thoughtful garden hygiene practices. 

  3. Use mulch to prevent soil splashing on to plant leaves.

Although sometimes plant ailments are inevitable. Should disease strike, here is a helpful checklist to identify what is going on:



One of the most common problems with plants is fungal disease. It takes many forms – mildew, mold, blight, rust, smut, scab, wilt and more. If your garden had any form of fungi last year, it is likely to have it again this year.  This stuff is persistent. So what can you do?


Water plants before noon. Fungi spores can germinate in just 6 to 8 hours. While watering at night may limit evaporation, it allows fungus to grow in moist conditions. Watering early in the day gives time for moisture to dry. 

Rotate crops. Never plant the same kind of vegetable or flower in the same place two years in a row.

Stop it before it starts. If your garden had a fungus in the past, the spores are still around, and odds are good the disease will be back. It usually occurs at the same time every year. The best time to start using fungicides, such as Revitalize, is early in the season. Repeat every 7 to 10 days throughout the growing season to keep spores from multiplying.


Solarize the soil. Lay black plastic sheeting on your garden preseason and let the sun cook the soil. This helps kill fungus spores.

Use drip irrigation to prevent fungal diseases.  This keeps the foliage dry and helps avoid spreading fungal diseases.  Do not work with plants when they are wet.

Plant disease-resistant varieties. If problems have existed in previous years, choose disease resistant cultivars.


Other tips: Mow under fruit trees. Move fallen leaves to the compost pile. Basically, remove dead or dying plant material that represents a hospitable site for fungus growth. 



Other common plant diseases are bacteria-based. These are spread through water and soil. Bacteria can enter a plant through wounds or through the natural openings in the epidermis called stomata. Generally, bacterial diseases cause rotting and wilting.

Sadly, bacterial diseases cannot be cured. The recommended action is to immediately remove the infected plant(s) from the garden. All of the affected plants must be removed to the trash can, even if they have only slight symptoms of bacterial disease.  Do not place diseased plants in your compost pile; the disease will be spread through the tainted compost.

To prevent the spread of bacterial disease, clean your pruning tools with a bleach solution made up of one part household bleach to four parts of water, or use Revitalize for a gentler solution. Wash your hands after handling infected plants to avoid transmitting the disease to healthy plants.



Viral diseases damage the plant by destroying the chlorophyll in cells, causing yellowing of the leaves. If a plant becomes sick and dies within a few days, suspect a virus. They work quickly!

Insects often carry viruses to plants, especially aphids, leafhoppers, mealy bugs, and whiteflies.  Aphids are the worst offenders; the green peach aphid can carry more than 50 different plant viruses. Viruses can also be transmitted on your hands or on garden tools.

Once they have taken hold, viral diseases cannot be cured. Remove and destroy the infected plants. Viruses can live on dead plant material for 50 years, so never add infected plants to your compost pile.

And finally: Always use Revitalize at the first sign of disease. We are huge fans of this product!


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fighting disease-virus-maize dwarf mosai
fighting disase-fungus-black spot on pap
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