"Weed" is a term used to refer to plants that grow where they are not meant to. Weeds are often plants that are the natives of an area, and grow in competition with other plants that have been planted. The disadvantage of weeds and grasses is that they compete for resources with beneficial plants and crops. Such resources include soil nutrients, water and sunlight. This is especially harmful to non-native plants, as they are even more sensitive to lack of any of the basic resources they need to grow and thrive.
Grassy Type Weeds
Grassy type weeds are the same as grasses; they germinate, grow and propagate in the same way as grasses do. Grassy type weeds are the most difficult to identify as they are very similar in appearance to the grasses that are planted and cultivated on lawns and gardens. Some examples of annual grassy type weeds are crabgrass, goosegrass, foxtail and quackgrass. Grassy type weeds compete for nutrition with turf grass on lawns and gardens, and often outgrow and smother the turf grass. Visually, they are far less appealing than turf grass.
Grassy type weeds can be controlled in many ways. Herbicides that target specific types of weeds are available. These products can either take effect before the seeds have germinated or kill the weed once it has taken hold. Grassy type weeds also tend to be shallow weeds so watering of lawns must be done deeply and less frequently. Maintaining a lush bed of high-quality turf grass by good cultural and environmental techniques is also important to inhibit the growth of grass type weeds.
Grassy Like Weeds
Grassy like weeds are also similar in visual appearance to grasses, but closer inspection will reveal a triangular stem that will distinguish these weeds from grasses and other grassy type weeds. Some common examples include wild garlic, nutsedge and Star of Bethlehem. Grassy like weeds show rapid growth rate and a physical appearance that is visually unappealing and incongruous to the rest of a high quality lawn. Application of herbicides is the most effective method of getting rid of grassy like weeds. The product must be applied in the early stages of development of the weed; once established, they are difficult to dislodge.
Broad Leafed Weeds
The most easily identifiable weeds are the broad-leafed weeds. As suggested by the name, they typically have broad, wide and flat leaves. They are visually and botanically very different from grassy type and grassy like weeds. Broad-leafed weeds are the most common and familiar types of weeds. Popular examples include violets, dandelions, chickweed, ground ivy, and white clover. The best method to keep away broad-leafed weeds is to follow good cultural and environmental garden practices to grow a dense and healthy bed of grass. Stubborn weeds can be removed by the use of appropriate herbicides.