Diseases happen in the garden. Pathogens find a susceptible host plant in a favorable environment and invade. The unfortunate plant may just show reduced health or may end up completely dead. When clients call Extension looking for a solution, there isn’t usually a magic bullet to employ. Part of the process almost always will include proper sanitation to reduce further disease.
Sanitation in the garden follows the same concept as personal hygiene. Pathogens of plants, like those of humans, could be bacterial, fungal, or viral. The goal is to remove the inoculum (part of the pathogen that causes the disease). But what does that look like practically in your garden?
First, don’t assume you are dealing with a disease. Symptoms from environmental, chemical, or physical injury can sometimes be confused for disease. Once you can identify the symptoms are really from a pathogen, you can learn more about where the pathogen is found and how to prevent future disease.
Removing dead or infected plant material is the number one step in most cases. Raking diseased leaves, removing fruits, pruning out diseased branches, and even pulling up entire plants are all examples of garden sanitation. Diseased material should not be composted. It’s important to disinfect your tools and wash your hands after working with diseased plant material and before handling healthy plants.
Black spot (caused by Diplocarpon rosae) of rose.
Williams Fountain, University of Kentucky, Bugwood.org
Weeds and insects can also harbor pathogens. Remove or prevent weeds that may also share certain diseases with your garden plants. Piercing sucking insects like thrips, aphids, and leaf hoppers are notorious for transferring diseases to the plants they visit. Once one plant in a row has been infected, insects can quickly spread the pathogen to neighboring plants.
Soil-borne pathogens are the most difficult to eradicate. The best we can do is try to avoid the movement of infected soil via tools, boots, pots, cages, etc. For a site with known soil pathogens, choose a resistant or non-susceptible plant. Use soil amendments to encourage beneficial organisms and improve drainage. Employ crop rotation in your vegetable garden.
Bacterial wilt (Ralstonia solanacearum) causing a rapid wilting of tomato plants.
Zachary Boone Snipes, ©2015 Clemson Extension
Just remember, we can’t control everything in the garden. Even with the most stringent garden sanitation practices, the garden will be exposed to pathogens. They arrive on the wind, via insects, birds, and mammals, and even from our activities.
For more information, see HGIC 2755, Integrated Pest Management (IPM), HGIC 2009, Integrated Pest Management (IPM) for Aphids, HGIC 1330, Crop Rotation, and HGIC 1600, Composting.
