Weeds like crabgrass and dandelions can ruin the smooth, lush look of a lawn. Every year, gardeners across North America spend hours trying to get rid of such weeds. Several lawn management strategies and tips can make weed control and removal easier. As with many garden problems, prevention is key when it comes to lawn weeds.
Cut the grass at the highest height recommended for their specific turfgrass species. This encourages deep root growth, making the turf stronger and more resilient, and also increases shade at the soil level to minimize the germination of weed seeds. The mowing heights for turfgrass varies by the grass species. The University of California publishes an online list of recommended cutting heights (see Resources).
A healthy, vigorous turf grows dense and resists weed invasions, according to the University of Wisconsin. Standard maintenance procedures like regular fertilization during the growing season, weekly deep irrigation--gardeners should moisten the dirt to a depth of 6 inches at each watering--and aerating in the fall can help maintain a healthy lawn.
Weed and Feed
Use a complete lawn fertilizer every eight to 10 weeks during the spring, summer and fall. This provides the grass with the extra nutrients it needs to grow. For weed resistance, use a weed-and-feed product that combines low levels of selective herbicides with standard fertilizer. Such products can be purchased from most garden stores and nurseries and will provide moderate weed control while feeding the grass in a single step.
Stop Weed Seeds
Homeowners should treat their lawns with a pre-emergence herbicide like oryzalin. This kills weed seeds and breaks the weed life cycle. The herbicide should be applied every year in the spring.
The manual removal of weeds has its place and is ideal for isolated weed problems, but more widespread issues like a severe crabgrass invasion should be treated with a selective herbicide. Such herbicides target common weed species without harming turfgrass. Choose a product that's formulated for the specific weed you're facing, and apply it according to its labeled guidelines since toxicity varies by product. Herbicides can typically be applied every 30 days if needed.