How to Use Weed Killers Without Harming Plants

Contact sprays, such as weed killer for plants, make it easy to kill weeds. Your weeding task is almost complete, no matter where the weedkiller lands. Sadly, weed killers do not always differentiate between your favorite flowers, valuable plants, and weeds. Try these tips to avoid accidentally damaging desirable plants when using weed killer.

Weed Killer Mishaps

Most spray-on herbicides are post-emergents, and they contain glyphosate as the active ingredient. This substance does not distinguish between undesirable plants and weeds. This type of herbicide kills any plant it comes into contact with.

Overspray, or spray drift, is what happens when this type of herbicide accidentally drifts on desirable plants. It can be the difference between killing unwanted weeds and killing an admired plant. Spray drift can cause leaf spots, stunted or dying stems, and leaf drop.

Follow these tips to prevent weed killer overspray or spray drift.

Protect other plants

• The label of the weedkiller is important. A popular weed-killer label warns against using high pressure nozzle sprayers because they can create fine spray particles.
• Spray weeds only when the air is calm. If the wind is too strong to spray, use a gel herbicide or paint the herbicide on the weed directly.
• Spraying weed killer on bulbs that are dead back is not recommended. Even when bulbs are dormant they can react to weedkiller that is sprayed into the neck.
• After each use, rinse sprayers and watering cans that are used to apply herbicides. Dump rinse water in an area that is not planted. Don’t dump the rinse water onto hard surfaces, as this will cause it to flow into nearby planting areas and street catchment basins.
• Use a dedicated sprayer or watering container for herbicides to avoid accidentally dosing desired plants with weed killer.
• Cover nearby plants with cardboard or plastic sheets to protect them from spray drift. After the herbicide has dried, remove the plastic sheeting.
• You should avoid walking over large areas that you’ve just treated. Otherwise, you may spread herbicides on your shoes to other areas like your lawn.
• When possible, spray on cloudy or overcast days. Spray drift symptoms are intensified by warm, sunny conditions.

Target the Weed

• Remove the top and bottom from a 2-liter plastic bottle, plastic milk can or metal food container to create a spraying zone. Spray the herbicide into the top of the opening. Place the collar over the weed. Use an open-ended box to spray a large patch of weeds.
• Cut a small hole in a plastic sheet to spray a weed that is growing between two desirable plants. The weed can be pulled through the opening in the plastic by laying it over the desired plants. Herbicide should be sprayed on the weed. After the herbicide is dry, remove the plastic.
• Use a U-shaped anchor pin to isolate weeds at the planting bed edge. Spray the weed once you have pinned and clumped the foliage.
• Use a sponge brush to apply herbicide only on the leaves of the weed you want to treat. Use a bristle brush to paint herbicide on leaves, but be careful not to spray it onto nearby plants.