- Always read and carefully follow chemical label directions.
- Carefully mix spray solutions in a separate container and strain through fine cheesecloth or household strainer to remove particles when transferring to sprayer.
- Wear protective clothing such as goggles, face mask, long sleeves, long pants, gloves, etc. to prevent contact with the chemicals.
- Tighten nozzle cap by turning clockwise for a fine spray. Turn counter clockwise to loosen nozzle cap for a coarser spray or solid stream.
- Spray in the coolest part of the day. Spraying in the heat of the day could damage plants.
- Never spray on a windy day because chemical drift could damage other plants.
- Spray all around the plants to catch trouble wherever it may start.
- Fine spray for flowers. Medium for shrubs and bushes. Course spray for weeds.
- Applying too much spray is a common mistake, harmful to the plants and wastes expensive material. Check chemical instructions to see how the spray is to be applied. Often it is only necessary to wet the leaves rather than to spray until it runs off.
- Always be sure to wash and rinse sprayer thoroughly after each use.
Proper application of insecticides, fungicides and herbicides is critical if they are to be effective and safe.
Chemicals must always be used as directed by the manufacturer. This can not be emphasized too strongly. Always measure carefully and never use on a windy day when drift can carry the chemical into areas you do not intend to treat.
Choosing the proper applicator for the type of chemical being applied is very important.
The applicator should allow you to:
- Dilute the chemical properly as directed in the instructions.
- Apply the chemical at the proper place. Sprayers with long spray wands and adjustable tips, help you reach all parts of the plant. Cover the stems, tops of leaves and under sides of leaves where insects hide and fungus diseases are often found.
- Apply chemicals in the proper spray pattern. An adjustable nozzle will give a fine mist to lightly cover the surfaces of the entire plant. Adjusted to a solid stream you get a long-reaching spray for tall shrubs, trees or climbing vines. Optional fan nozzles give a flat spray for evenly covering larger areas such as lawns.
- Control the spray easily and quickly so you can stop spraying just as it begins to run off; prevent chemical waste, harm to the plant from over spray, plus reducing drift into surrounding areas.
Problems with sprayers that do not function properly can often be traced to corroded metal parts, clogged nozzles or damaged seals.
Rust and corrosion are often caused by leaving chemical solutions in sprayers and can be prevented by cleaning after use. Clogging often happens when dirt or undissolved particles of powdered chemicals get into sprayer hoses and nozzles. These same particles also damage seals.
To prevent clogging, premix dry powders in a separate container with the recommended amount of water, mixing thoroughly before pouring into the sprayer. If spraying wettable powders, use a paint filter or household strainer to filter out undissolved particles when pouring mixture into the tank. It would also be a good idea to shake the sprayer occasionally while spraying to keep the solution mixed.
If the nozzle becomes clogged, remove it from the spray wand and clean with a toothpick or broom straw. If this fails, reverse flush with water until the blockage is dissolved or flushed out.
To avoid cross contamination between chemicals, corrosion or clogging, clean the sprayer after each use with a small amount of soap dissolved in water. Then rinse with clean water until the sprayer is completely clean. Empty and dry sprayer, then store in a dry place.
Cleaning is very important if a herbicide was used in the sprayer because any remaining residue could damage plants sprayed at a later time. It is usually best to keep a separate sprayer for weed killers only and have it clearly marked.
Petroleum solvents, strong acids and bases can also damage seals. The solution is usually to get a special chemical resistant sprayer with Viton® seals.
Repair kits are available for homeowners to make minor repairs such as replacing the hose, discharge valve, nozzle, pump cup or O-rings.
Viton® is a registered trademark of DuPont Dow Elastomers.