Weeds of the Lawn & Garden

"Stray" ornamental plant growing in joint between sidewalk and foundation
A weed is defined under the Federal Insecticide, Fungicide and Rodenticide Act as any plant which grows where not wanted.    The term could apply to both terrestrial plants found in the lawn or garden or aquatic plants found in ponds, lakes and other bodies of water.  Weeds can compete with nearby plants for valuable resources such as sunlight, nutrients and moisture thereby affecting the health of desirable plants in the lawn or garden.  When growing in cracks or crevices of sidewalks they can accelerate the deterioration of the concrete as they grow and their roots expand.  They can also prevent water that is flowing across the surface from draining which results in standing water or small amounts of moist debris to collect. 

Virginia Tech has developed a Weed Identification Guide to help with the identification of common weeds and weed seedlings which occur in Virginia.  The guide includes a Grass Weed Identification Key to aid in identifying unknown grassy weeds.  As an alternative, either NC State’s TurfFiles Centere website or the University of Georgia’s weed identification database can be valuable resources.  When trying to identify unknown weeds you will need to pay attention to different attributes of the plant so it may be helpful to either have a whole specimen available or to take several photos.  In both cases, note the type of roots as they may also be used to help identify the plant.  If you need help further identifying a specific insect you can contact your local cooperative extension office.

Options for Managing Weeds:
  • Cultural Controls include the use of various mulches or landscape mesh to prevent or retard weed growth as well as improving the growing environment.  For lawns, it can also include maintaining plant health to encourage healthy growth by selecting the correct turfgrass species for your area of the state, determining fertilization needs and by adapting mowing practices. 

  • Biological Controls, if they are available, may include the use of an insect or microorganism to discourage or prevent weed growth.

  • Mechanical Controls include physical removal or destruction of a weed.  Techniques include hand pulling, use of tools, solarization, shading or torching.

  • Chemical Control involves the use of organic and conventional herbicides to manage weeds.

Virginia Tech has compiled various Pest Management Guides which provide information about various control options.  The Home Grounds and Animal guide includes chapters with information about managing weeds which are commonly found around the home, lawn or garden.

Other Resources from the Virginia Cooperative Extension:

Additional Management Resources for Specific Weeds
(Click on Photo if shown)

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Broadleaf Weeds

Moss
Mosses

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Mushrooms

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Poison Ivy

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Wild Violet (UMD)

Star of Bethlehem (UMD)

Annual bluegrass (Poa)

Horsenettle

Spurweed (Burrweed)

Unless otherwise noted the above links take you to resources found on the Virginia Cooperative Extension. Upon selecting a link, you will be redirected to the VCE website where the resources are located. These resources and others can also be found through the Pubications and Resource page of the Virginia Cooperative Extension website.