Public Works and Environmental Services

CONTACT INFORMATION: Our administrative offices are open 8 a.m. – 4 p.m. Mon - Fri - In-person meetings by appointment only.
703-324-1770 TTY 711
12055 Government Center Parkway
Suite 518, Fairfax, Va 22035
Brian Keightley
Division Director, Urban Forest Management

Forest Health – Prevention and Treatment of Diseases and Infestations

Setting Up Your Trees for Success

The easiest and most effective way to reduce the impact of insects and diseases that could harm your trees is to reduce environmental stress on the tree. Stresses like drought or poor soil impede your tree’s ability to defend itself against an attack. Trees that are properly maintained and growing under optimal conditions are also less likely to develop costly problems as a result of stress. Tree owners can take simple steps that go a long way toward improving the vitality of their trees and ensure they get the most benefit from their trees in the long-term.

Right Tree, Place
Plant Native
Native plants
Invasive Species
Hire An Arborist
Not All Bugs Are Bad

Not All Bugs are Bad

Ground BeetleGenerally, people perceive insects negatively. Much attention is focused on harmful insects that threaten people of the health of trees. However, there are numerous beneficial insects that provide many functions that are vital to a healthy urban forest ecosystem including pollination, serving as food for birds and wildlife, and control of tree and garden pests. These include bees, ground beetles, parasitic wasps and flies, lacewing larvae, and many more. Often, it’s the lack of natural enemies that allow destructive insect pests to flourish. The Virginia Cooperative Extension has a variety of helpful publications and resources on the topics of insect pest identification and management. If you need help identifying an insect or disease, then try seeking the assistance of a Fairfax Master Gardener.

Integrated Pest Management

Integrated Pest Management (IPM)

Fairfax County follow an integrated pest management (IPM) strategy to accomplish its goals of mitigating and preventing spread of forest pests and diseases in the county.  IPM is an ecological approach to pest control which combines multiple strategies including chemical, cultural and biological methods with the goal that chemical control should be the last resort.  Successful implementation of an IPM program results in effective control of the target pest while reducing pesticide use and harm to non-target organisms and the environment.

IPM at Home

Residents can begin by evaluating the problems they are having with their landscape and identifying the correct pest that is causing the problem, or if a pest is even the cause of the problem.

Prevention should be the primary goal in IPM.  However, when that isn’t possible, cultural controls can be extremely effective and relatively easy to do.  Some examples include: water and nutrient management, reducing competition, installing disease/pest resistant cultivars or species, removing weeds, physical removal of pest or infested plants, mulching and proper pruning.  Biological control may involve attracting predators or parasitic insects or releasing predators, pathogens or other organisms that may control the target pest.

Finally, chemical controls should only be used if alternative controls have not been effective.   Pesticides should not replace alternative controls entirely and are merely another tool in the IPM toolbox.  Choosing the right pesticide means having the pest identified, read the label to ensure the pest may be treated with the active ingredient you choose and select an active ingredient as specific as possible to the pest you are treating.  For example, Bacillus thuringiensis or Bt has many strains that are specific to mosquitos, beetles and moths/butterflies.  For more information please visit Pesticide Environmental Stewardship - Select a Pesticide

If you need assistance with identifying a pest that is damaging your garden or landscape contact the Virginia Cooperative Extension or speak to a Fairfax Master Gardener. For more information about the IPM read Integrated Pest Management for Vegetable Gardens, or A Virginian’s Year-Round Guide to Yard Care.

Aphids are preyed upon by parasitic wasps and lady beetle larve as they feed on milkweed.
Aphids are preyed upon by parasitic wasps and lady beetle larve as they feed on milkweed.
caterpillar with eggs
Tiny oval cocoons of a parasitic wasp along the back of an unlucky tomato hornworm.
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