Sprayers will effectively combat a wide variety of lawn and garden pests. They are used for applying liquid pesticides, whereas dusters are used for applying dry pesticides. The chemical pesticides or herbicides that are used in sprayers either come in liquid form, in water-soluble form, or as wettable powders. Wettable powders do not dissolve; they are kept suspended in the water while being sprayed on the plants.
The chemical concentrate is always mixed in the sprayer’s container, according to the manufacturer’s specifications detailed on the label.
To determine which type of sprayer to buy, consider the advantages and disadvantages of each. Hose-end sprayers don’t require pumping, and while their range is limited by the hose length, they put out a large volume quickly, which you’ll want for lawns or massed shrubs.
Compression sprayers generally have a 1- to 3-gallon capacity, can go anywhere, and are more precise, but they are somewhat more likely to get clogged. It’s best to keep to the sprayer with a 2-gallon capacity; larger compression sprayers are heavy when full, which makes them difficult to carry around.
Backpack sprayers usually hold 5 gallons of mix. The tank is carried like a backpack, which makes the considerable weight more wieldy. They require frequent pumping with one hand while the other directs the spray.
Slide-type (trombone) sprayers can produce the farthest-reaching stream, but they require continual pumping and the stream is not constant.
All sprayers, whatever their type, have two problems: their metal parts tend to corrode unless kept clean, and the nozzles can clog up easily.
Sprayers are made of materials that are highly resistant to corrosion, such as brass, stainless or galvanized steel, or plastic. Regardless of the material, all sprayers should be thoroughly cleaned after use or the chemicals will eventually cause problems and erode the material.
Fittings on sprayers used to be made of either brass or galvanized steel, but high-impact plastic is now used widely, even in the best equipment, since it is less prone to corrosion or rust.
The nozzle is most subject to being plugged by small particles of grass or dirt. It should be easily removable for cleaning. Two types are commonly used in home gardening: hollow-cone nozzles and flat-fan nozzles. The hollow-cone nozzle is used to spray pesticides and fungicides on shrubs. It can be adjusted from a thin stream to a fine mist. A flat-fan nozzle is best for applying herbicides; it gives more precision and control.
The sprayer tank should have a wide mouth for convenient filling. Many have a funnel-shaped top, which directs any chemicals or water that may spill around the edges during filling to run down into the tank rather than down the sides. The wide top also makes it easier to rinse and drain the sprayer and to thoroughly wash out any particles of debris in the tank that can clog the hose.
Also took for a good, solid base. This will keep the sprayer from tipping over while you are pumping air into it.
Valves and Hoses
Some of the new compression sprayers have safety valves that automatically open when the pressure reaches a sufficient level. These valves can also be used to release the pressure in the tank when you’re finished spraying. This is a more convenient way to release pressure than by unscrewing the top.
The hoses should be of two- or three-ply reinforced rubber or vinyl to resist cracking.
There should be at least one filter (usually located at the base of the wand) that can be quickly removed and cleaned when necessary.
For small jobs around the house or patio, use the trigger sprayer—a simple plastic squeeze-pump mounted on a plastic bottle. Commonly used as misters, this inexpensive sprayer also works well for applying pesticides to outdoor plants. If you use it for pesticides, though, be sure to mark the bottle clearly and to use it only for that purpose. (Use another bottle for misting with water.)
A hose-end sprayer consists of a device that proportions solution into a stream of water and a container for the mix. They are screwed onto the end of a garden hose. The force of the water draws up just the right amount of concentrate into the stream of water.
Older types use a glass or plastic jar suspended beneath a nozzle that attaches to the end of a hose. The jar contains the spray concentrate, and the nozzle mixes that concentrate with the stream of water.
Many hose-ends have a fixed mixing ratio built into the nozzle. This ratio can vary from 5:1 (5 parts water to 1 part concentrate) to 14:1. Because this ratio (as well as the mixing ratio called for on the chemical bottle) can cause some confusion for first-time users, here is an example of how it works.
To decide how much pesticide to put in the bottle, multiply the amount of chemical the directions call for per gallon of water by the first number in the mixing ratio (5 if the ratio is 5:1, or 14 if the ratio is 14:1 ). Let’s say that the directions on the chemical you are mixing call for 1 tablespoon of chemical to 1 gallon of water and that your hose-end has a fixed mixing ratio of 14:1. First put 14 tablespoons of chemical in the jar, and then add enough water to raise the contents to the 1-gallon mark on the side of the jar. The hose-end mixes this concentrate with the water so that it comes out at 1 tablespoon of chemical to every gallon of water going through the hose.
Some hose-ends are adjustable, in which case you don’t have to premix. A dial on the top has up to 16 different settings for whatever dilution you desire. The blending and dilution is all done in the spraying head. Just pour the chemical in the jar; the sprayer takes care of the rest.
This type also saves you money, since there is no leftover mixture to throw away—you can pour the unused portion of undiluted chemical back into its original container.
There are also hose-end nozzle heads that attach directly to the original chemical bottle. This is the simplest system of all. When you’re finished, just clean out the nozzle head.
The newest types of hose-end sprayers don’t require you to do any figuring at all. Just screw a cartridge containing the pesticide onto the sprayer, and the sprayer automatically meters the right amount into the water stream.
Hose-end sprayers have adjustable nozzles for covering a wide area with a mist, a fan-shape spray, or a straight stream (for reaching tree tops). The nozzles can also be adjusted to direct the spray up against the underside of plant leaves.
The versatility of these sprayers makes them the most widely used type. They are relatively light and portable, and their wands and adjustable nozzles make application precise. You can buy 1-pint up to 1-gallon capacity sprayers for the greenhouse or potted plants or 2- to 4-gallon sizes for general lawn and garden work.
To operate these sprayers, first add the proper proportions of chemical and water to the tank, and secure the top. Then, with a handle, pump air into the tank until pressure builds up. When you’re ready to apply the pesticide, press the trigger. This opens a valve at the end of the hose, and the compressed air forces the liquid spray out the nozzle.
The nozzle can be adjusted to deliver a fine mist for dense, low-growing plants. Larger models emit a 15- to 30-foot stream to reach tree tops. The size of the wand varies according to the size of the entire unit, but most are long enough so that you can spray close to the ground or the underside of leaves without having to bend over.
These sprayers usually require you to pump up the pressure twice in order to empty the tank. The air trapped in the tank forms the compression that forces the liquid out of the nozzle. When you first fill it, only a small amount of air is trapped in the tank. After spraying for a while, the compression is used up and you need to pump it up again. This time, however, more air is available to be compressed, and the compression usually lasts until the tank is empty.
Larger tanks usually have a strap for carrying the unit over one shoulder. For small jobs around the greenhouse or garden, the quart-size compressed-air sprayer is convenient. The spraying head is mounted on a plastic container that unscrews to be filled or cleaned. A plunger on the spraying head is pumped to force air into the container. The short spraying wand is attached directly to the head. The nozzle can be adjusted from a fine mist to a direct stream.
For large jobs that require you to do extensive walking, the backpack pump sprayer is worth considering. Made of high-impact plastic or galvanized steel, this type handles up to 5 gallons of spray mix. The displacement pump is operated by constantly working a lever with one hand while directing the spray with the other.
The pump handle is often linked to an agitator in the tank, which keeps wettable powders in suspension and prevents them from settling to the bottom.
The nozzle can be adjusted from a fine mist to a standard spray to a 40-foot stream.
Although backpack pump sprayers are contoured to fit your back and equipped with padded, adjustable shoulder straps, you need strength to carry them around. The container alone weighs 8 to 15 pounds, and water adds about another 8 pounds per gallon. However, the heaviness of the pack is offset by your ability to go longer between refills (since it contains a lot of solution) and by the relative ease of carrying a 40-pound pack on your back rather than a 25-pound sprayer over one shoulder.
These trombone-action sprayers are pumps, not compression sprayers. The pump, which is built into the handle, has an action that works on both the push and pull strokes to maintain a constant stream. This type of sprayer throws the spray further than any other type of hand-operated sprayer, which makes it quite effective for spraying fruit trees. It is best suited for high-pressure spraying jobs around the home where you don’t have to keep moving the bucket.
You pre-mix the solution and place it in a bucket, then drop the end of the trombone hose into the bucket. The hoses are about 6 feet long and the end in the bucket has a filter screen. The hose has a clip or a heavily weighted end to keep it from pulling out of the bucket. The pumping action sucks the spray out and forces it out the nozzles.
The nozzle rotates up or down for spraying the undersides of leaves and adjusts from a spray to a stream reaching 25 feet or more. Wand extensions of up to 9 inches are available for greater reach.
The 1-quart-capacity brass slide pump and nozzle is a powerful but compact spray gun that’s mounted on a plastic bottle. The nozzle adjusts from a spray to a stream. These are excellent for spraying roses and other flowers near the house.
Use common sense when using pesticides. Work on calm days; if there is a slight breeze, spray with the wind at your back, and back away from what you have sprayed. If your skin tends to be sensitive, wear long sleeves and gloves when working with the chemicals. Rubber kitchen gloves or disposable plastic gloves will repel spilled liquid chemicals without hampering your dexterity.
Dust masks and respirators offer protection against the inhalation of chemical spray or dust. If the chemical is blown back over you, the masks and respirators don’t block it completely, but they do screen out most of it. They generally are only necessary when you’re working on trees, where the spray goes up and then settles down around you.
If possible, don’t use one sprayer to spray both pesticides and herbicides. Use two different sprayers, and mark each one clearly. If you do use only one sprayer, take extra care to clean it thoroughly after using it.
Keep your sprayer clean or corrosion will result. After spraying, unscrew the nozzle and check to make sure it isn’t clogged. Empty the container, and dispose of any leftover chemical according to the directions on the pesticide label. Then thoroughly rinse out the container three times. During the last rinsing, put the top on the sprayer and run water through the hose and nozzle.
Apply oil to moving parts as required; follow the directions on your particular sprayer. The gaskets on pumps are usually made of neoprene rubber or leather and need an occasional oiling.
Nozzles often have a small filter that should be cleaned regularly. This is especially important when toxic materials have been used.
Hang the sprayer upside down when it’s not in use so that it can drain and dry completely.