Weed killers are designed to kill plants that a gardener does not want growing in a certain area. Weed killers are applied in a variety of ways, the most popular of which is to spray weeds with a spray bottle or chemical sprayer. If the chemical that you are applying also lands on desirable plants, it is known as overspray, which leaves distinctive signs.
Decline of Desirable Plants
Overspray often lands on plants that you don't wish to damage, such as turf grass or landscaping plants. These plants will exhibit signs of the herbicide's presence by either dying or declining in health. A dead plant often has curling, browning and yellowing foliage. Shrubs and trees may also have a reduced canopy. Depending on the size of the plant, it may take years to recover from overspray.
Patchy or Dead Turf
Turf grass that has been affected by overspray may have a spotty yellowed appearance that resembles a drip or pour pattern. As the grass declines its density will decrease. Eventually the grass will appear patchy with soil visible through the clumps.
Weed Killer Waste
Weed killers are often sold in concentrate form. If you are applying a selective weed killer such as a broadleaf herbicide in turf grass to kill creeping ivy, you will measure and mix a specific quantity for use in your lawn. Running out of weed killer before you planned to may be your only sign that you may have wasted the weed killer through overspray. Overspray of a broadleaf weed killer will not show up in turf grass, which is resistant to the herbicide.