You can use a hose-end sprayer to mix and dispense exactly the proper concentration of liquid and even water-soluble powder weed killers, pesticides, fungicides and fertilisers. Both adjustable-flow and fixed-rate hose-end sprayers are available for use with different brands and types of lawn and garden care products. An adjustable-flow sprayer dispenses different concentrations of chemicals depending on how you set the dial, whereas you need to mix the concentrate with water in a fixed-rate sprayer. Pre-mixed concentrates are also packaged in a disposable, single-setting hose-end sprayer. All types of hose-end sprayers are simple to use.
Put on your rubber gloves and eye protection.
Open the jar of the sprayer by unscrewing it from the sprayer head. Add undiluted concentrate according to the directions on the package of the product you are using. You can usually use the gradations that are imprinted on the side of the sprayer jar to determine the amount of concentrate you have added, but you may need a measuring spoon if you are adding a very small amount of product.
Set the dial to correspond to the number of gallons of spray you need to dispense for the amount of concentrate you added. The dial is usually at the base of the sprayer head, above the threaded cap that secures the sprayer jar, and on most models you rotate it so that the indicator arrow points to the number of gallons of spray you want to produce. For instance, if you added 1/4 cup of weed killer to the jar, and the bottle instructions say that 1/4 cup makes 20 gallons of spray, then turn the dial so that the indicator arrow points to "20."
Connect your garden hose to your faucet with the faucet turned off. Screw the outside threaded end of your hose into the hose inlet of the sprayer and securely tighten it.
Turn your faucet on to about 3/4 of its pressure capacity. Adjust the tip of your sprayer nozzle if you wish according to instructions for a finer or coarser spray pattern.
Pull or push down on the trigger or handle of your sprayer to spray the solution while you walk at an even rate across your lawn or garden so that the chemical is evenly distributed. If you see that you are spraying more than you had expected, or using more spray than you mixed for the size of the area you are treating, either use a lighter amount of pressure on the trigger or handle, or turn your faucet slightly toward the closed position to lower the water pressure.
Finish spraying the area you wish to treat. If you have any leftover concentrate, open the jar and pour it back into its original bottle.
Fill the sprayer jar with clear water and reattach it to the sprayer head. Set the mixer dial to the highest gallon setting and spray with as much pressure possible on the trigger until the sprayer jar is empty. This rinses the sprayer and keeps it in optimal working order.
Turn off the water at the faucet. Unscrew the sprayer from the hose and store it in a convenient place.
Remove the sprayer jar from the sprayer head. Put on your rubber gloves and safety goggles.
Add the proper amount of concentrate to the spray jar according to the instructions on the label of the product you are using.
Add water to fill the spray jar to the level that corresponds with the number of gallons of spray you need. For instance, if you are using a 10-gallon sprayer and you need 5 gallons of spray, you would add enough water so that the contents of the jar reaches the 5-gallon mark.
Reattach the sprayer head to the sprayer jar.
Shake the jar well.
Screw the outside threaded end of your garden hose into the hose inlet of your sprayer and make sure your hose is connected to your faucet.
Open your faucet about 1/2 to 3/4 of the way.
Open the valve of your sprayer, which is usually located on the top of the housing between the nozzle and the hose inlet, so that spray begins to exit from the nozzle.
Let the jar fill up and begin spraying the area you need to treat by walking evenly while you hold the sprayer. Slow down if you find you are using too much spray to cover the area you need to cover and walk faster if you are using too little.
Finish spraying the area. Close the valve of your sprayer and remove the sprayer jar. Dump any excess concentrate safely; do not dump it in an area where children or pets might play and do not dump weed killer near plants or trees.
Fill the jar about halfway, reattach it to the sprayer head, and turn on the valve so that you spray out the contents of the jar and rinse your sprayer.
Close the sprayer valve, turn off your faucet, and unscrew the hose from the sprayer. Store your sprayer in a convenient place.
Make sure your faucet is turned off and that your garden hose is secured tightly to the faucet. Put on your gloves and eye protection wear. Shake the sprayer bottle well if directed to do so on the label instructions.
Screw the sprayer on to the outside end of your garden hose. Make sure the sprayer is in "Off" or "Locked" position by checking and adjusting the lock tab or spray bottle dial.
Turn your faucet on about 1/2 to 3/4 of the way.
Open your spray bottle valve or nozzle with the lock tab or the dial and begin spraying. Walk at an even pace as you cover the area to be sprayed.
Finish spraying the area. Close the valve or nozzle of your sprayer once again and then turn off your faucet.
Open the valve or nozzle dial or lock and wait for any liquid to stop flowing. Close the valve dial or nozzle lock again. Unscrew the bottle from the hose. Store the bottle out of the reach of children and pets if any concentrate remains, or safely dispose of it by wrapping it and putting it in your outdoor garbage disposal if it is empty.
Lawn chemicals are harmful or fatal if swallowed and can irritate skin and mucous membranes. Do not spray on or near children or pets, wear rubber gloves and eye protection, and change your wet clothing and shower as soon as you are finished spraying. Wear a face mask as well if you are sensitive to chemical mist.