Choosing A Sprinkler
When choosing a sprinkler, several factors should be considered. The size and shape of the area to be watered, the soil type, and the rate of water flow are all important. Soils containing a large amount of clay should be watered more slowly and less often than soils that do not contain clay. Clay soils are slow to absorb water, but will retain it for longer amounts of time. Sandy soils are the opposite. They absorb water very quickly, but it drains out of them almost as fast. Loamy soils fall somewhere in between.
There are 5 general types of sprinkler available: impulse, oscillating, rotary, stationary and traveling.
Impulse sprinklers have a single water jet that sits close to the ground. It is less subject to clogging than other types and it's positioning helps make it wind resistant. It waters a large area slowly in a circular pattern. Better models can be set to water only a partial circle as well. It uses a lower water pressure and flow rate than other types of sprinkler.
Oscillating sprinklers spray many jets of water out of a long tube which runs the length of the unit. This type of sprinkler waters large areas quickly in a rectangular or square pattern. This sprinkler uses gears to turn the tube slowly back and forth. When in use, the water tends to look like a fan.
Rotary sprinklers are great for more medium sized gardens and lawns. They consist of a base and a spinning unit with 2 or 3 arms. The arms have water jets on the ends. Jets on some models are adjustable. Rotary sprinklers lay down water quickly, generally one inch per hour. Some types come with adjustable high rise bases as well.
Stationary sprinklers are built low to the ground usually on sled type bases. There are several different types of designs. One type is a ring with several rows of holes through which the water sprays. It will water a small garden in a circular pattern. Another type is the "salt shaker" style. These come singly or with several on a turret which can be turned to adjust the pattern shape. Stationary sprinklers are usually the lowest cost sprinkler.
Traveling sprinklers follow the garden hose (which you lay out in the pattern you wish them to follow) or a guide line on wheels attached to the base. They water large irregular patterns over the course of several hours. Two rotating arms spray water in a circular pattern as the sprinkler follows its guide. These can be adjusted in or out to vary the diameter of the spray circle. If you choose this type, make sure it has an automatic shut off valve.