Stress your lawn, invite weeds! Anybody have henbit? Weeds are opportunists, taking advantage of open spaces in thin, weak stands of turf. Although improper fertilizing, watering, and mowing are the most common causes of poor lawns, insects and diseases can also expose the lawn to weed invasion. Always try to determine why weeds invaded the lawn and correct the problem. If the basic cause is not corrected, weeds will return even though existing weeds may be eradicated with herbicides.
*Improper mowing. Mowing too low and too infrequently thins the turf, allowing weeds to get started.
*Improper watering. Frequent watering encourages weed seed germination, disease, thatch, and a shallow rooted turf that is less competitive with weeds for soil moisture and nutrients.
*Improper fertilizing. Fertilizing too much, too little, or at the wrong time may benefit weeds more than grass.
*Insect and disease injury. Weeds rapidly invade lawn areas that are thinned by insects and diseases.
*Compacted soil. Soil compaction is a hidden stress on the turfgrass root system. The grass is unable to compete effectively with weeds. Clay and silty soils are especially prone to compaction.
*Excessive wear. Turf areas that are used for recreation and sports are subjected to wear and compaction. Weeds become a problem in these areas, requiring intense weed control and turf management.
*Wrong kind of grass. The wrong kind of grass for the location will gradually decline and be invaded by weeds.
*Environmental stress. Weeds often take over a lawn after it has been weakened and thinned from weather related stresses.
*Thatch. Excessive thatch causes shallow-rooted grass and contributes to insect and disease problems, which are followed by weed invasion. Thatch also can reduce the effectiveness of some soil-applied weed control chemicals.