Green, grassy lawns provide hours of enjoyment for families in backyards and add curb appeal to homes. Yet, weeds can sprout in even the best-tended lawn. Weeds can be a sign of problems with the soil in your yard. Soil that does not drain or is low in nutrients encourages weed growth, as does soil that is compacted due to overuse. You'll need to find out what the problem might be, instead of just pulling weeds, in order to eliminate weeds from your lawn.
Remove weeds and roots from the area where lawn will be planted. The best way to eradicate weeds in your lawn is to prevent them. Before you lay sod or seed the lawn, buy a dandelion weed puller and use the tool to dig down to get the roots and rhizomes to prevent future weed growth. You can purchase the tool, which has an end that looks like a thin fish tail, at a local garden center.
Spread pre-emergence herbicide on existing lawn, one time in January, February or March. Apply again in September, unless you plan to seed the lawn in the fall. Pre-emergence herbicides require 1/4 to 1/2 inch of irrigation for activation. Water with an overhead sprinkler for about 30 minutes. Stick you finger into the soil about 1/2 inch. Continuing watering if soil does not feel moist to that depth. The herbicide kills the weeds before they germinate. If you wait until later in the spring, when weeds have germinated, you will need to use other herbicides.
Test the lawn soil to determine if there is an underlying cause for the weeds. Use soil test kit to check the pH and mineral levels of your lawn soil. Soil lacking in nitrogen or phosphorous attracts weeds such as clover or other legumes. Fertilize the lawn to maintain levels of nitrogen, phosphorous, potassium, calcium and aluminum as needed and recommended for your grass type. If soil pH is lower than 4.5, add lime to bring pH levels to 6.5.
Aerate compacted and bare sections of lawn. Rent a plug aerating machine that will remove soil from the lawn, rather than one which just creates holes. This allows more air and water to get to grass roots. Seed bare spots in fall. Compacted lawn spots are usually high traffic areas near sidewalks or swings. You can also hire a lawn service to aerate your lawn.
Water lawn deeply once a week during growing months. Short periods of irrigation encourage shallow roots, which is ideal for weeds but hurts your lawn. Deep watering will keep your grass healthy and prevent weeds from cropping up.
Overseed the lawn. Using the grass of your choice, seed your lawn in the fall. According to lawn care expert, Jon Daly, author of "How to Create a Green Lawn," overseeding is the best way to prevent weeds.
Hand pull weeds when they are still young. Use a dandelion weed puller to pull weeds out of yard. Discard weeds.
Spray weeds with clove oil for organic yards, or purchase a herbicide and spread across entire yard during season. Three-way (2,4-D + dicamba + MCPP) herbicide is effective in killing weeds from April through July, and again in midfall. Don't use this herbicide if you plan to seed the lawn.
Burn weeds using a flamer or torch. Purchase a self-igniting flamer to avoid having to use matches. Point the flame at the weed and burn for a few seconds. Do not use this during dry periods or windy days or if the yard has dry undergrowth.