A dense, healthy turf is the best deterrent to broadleaf weeds. Practices that increase weed infestation in a lawn include mowing short, poor fertilization practices, and frequent, light watering. Diseases or insects that thin a lawn can result in unwanted weeds growing in the voids. The seeds of broadleaf weeds occur naturally in all soils, and they persist for 30 or 40 and sometimes as long as 50 years.
Most broadleaf weeds are prolific seed producers.
Many produce thousands of seeds per plant. Boxes of cheap grass seed may have many unwanted broadleaf weed seeds. Any lawn has the potential to develop a weed infestation. Another technique is the use of broadleaf herbicides. Products with more than one herbicide component will control a wider spectrum of broadleaf weeds.