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Plant Pests and Diseases


Find information about safely and effectively controlling problems in your garden here! 

The following links will direct you to information and pictures that will help you to identify any pest or disease that you may have in your garden. It is important to correctly identify a problem before you begin treating it. These websites will provide you with information on how to control the problem using the least-toxic method as defined by Integrated Pest Management.

See below for our Top 21 "offenders" 

Meet the Beneficials: Your Friends in the Garden

Look below for other problems by type of plant:

Find Pests and Diseases of:
Trees and Shrubs
Fruit trees
Fruit Trees
UC IPM Site – more information

IPM, or Integrated Pest Management, helps you to control garden pests (including insects, diseases, and vertebrates) by effectively reducing problems using the least toxic methods that sufficiently control the pest. This scientific and environmentally sensitive way of looking at pest management walks you through several techniques if necessary to safely minimize or eliminate the pest.

UC Pest Notes

Have a problem with an insect, disease, or vertebrate pest? Check the list of UC Pest Notes for in-depth solutions to your specific problem. Pest Notes are peer-reviewed publications about specific pests or pest management topics directed at California's home and landscape audiences; they are based on UC's IPM recommendations.


Meet the Beneficials: Your Friends in the Garden


Beneficial insects are the natural enemies of garden pests, they help keep our garden’s ecosystem in balance. Green lacewings are generalist predators, with the adults eating nectar and pollen and the larvae feeding on mites, eggs, and small insects such as aphids and thrips. Lady beetles (in larva and adult state) prefer aphids but also eat whiteflies and other soft-bodied insects. Invite them into your garden by choosing plants that provide them shelter, pollen, and nectar and avoiding pesticides that kill them. 

See a variety of natural enemies in this poster from UC IPM 


Reduce Pests and Diseases By Changing Your Cultural Practices

Pest Barrier in a raised bed with a hoop frame to support covering to prevent pests.

Learn more about how to avoid or prevent garden pests with cultural practices (i.e. barriers, planting schedules, and selecting disease-resistant varieties) see Reduce Pests and Diseases By Changing Your Cultural Practices