Controlling weeds and unwanted grasses is part of landscape maintenance. Weeds tend to be invasive and rob the turf, garden plants and flowers of nutrients. Taking certain preventative measures reduces the germination of weeds. Your routine maintenance should also include monitoring for new weed growth and eliminating those weeds before they flower or propagate.
Weeds fall into two broad categories: grassy weeds (or weedy grasses) and broadleaf weeds. Grassy weeds emerge as a single leaf weed, or monocot. Crabgrass and quackgrass are monocot weeds. Broadleaf weeds emerge as a two-leaf plant and are referred to as dicot weeds. This category includes dandelions, ground ivy and chickweed.
Grassy weeds usually grow within an existing lawn. Crabgrass may establish itself within a lawn early in the growing season if the lawn was seeded too thinly. Seed from any unwanted grassy weed take advantage of a thinly seeded lawn, unhealthy soil or a poorly irrigated landscape.
Broadleaf weeds invade lawns and pop up in flower beds, vegetable gardens and in sidewalk cracks. These weeds mature quickly and have wide seed dispersal.
Preventative measures are important in controlling both types of weeds. Well-aerated, nutrient-rich soil densely seeded for the lawn area creates a thick lawn. Denser grass "crowds out" potential weed seedlings and minimizes the opportunities for grassy weed seeds to germinate.
Another form of prevention is the use of a pre-emergent herbicide. A chemical application, a pre-emergent should be applied to the turf area before seed germination. Check the label to ensure the application is designed to kill just the weedy grasses and not the turf grass.
In flower beds and gardens, use landscape fabric. When digging the beds, install landscape fabric to act as a protective barrier to soil-embedded seeds. Add mulch to the soil surface to discourage seed germination of broadleaf weeds.
A broad spectrum herbicide may be applied to broadleaf weeds. Use a spray applicator to douse individual weeds as they emerge. This method is most effective if the herbicide is applied before the weed flowers. Select an herbicide that is designed to kill the root of the weed.
Post-emergent herbicides are also available for grassy weeds. As with pre-emergent applications, though, ascertain from the label that the chemical is designed to kill only the specific weeds invading the turf, and not the turf.
Pulling weeds by hand requires a more consistent monitoring, as an abundance of weeds make this method impractical. The advantage of pulling broadleaf weeds by hand is the assurance the roots are destroyed.
Several types of weed removal tools are available. They usually have a sharp, two-pronged end that is pushed into the ground alongside the weed. The prongs "grab" the weed roots, and when the tool is pulled upward, the weed--roots and all--is pulled away from the ground. This method is most effective when used at the first sign of broadleaf weed emergence.