There are at least four types of drip systems suitable for typical yards and gardens. They include soaker lines, porous soaker lines, emitter systems, and micromisting systems.
The drip soaker system is simply a hose with lots of holes punched in it that allow the water to drip slowly out of the hose for its entire length. You lay the hose along the bed and turn on the water just a little bit so that the water seeps slowly into the ground. Most garden supply stores carry this product. A drawback of drip soaker systems is that it is impossible to regulate the water pressure along the length of the hose to achieve uniform watering along its length. More water will come out close to the faucet, with much less water coming out at the far end of the system. Furthermore, these hoses are difficult to lay up and down a bed without having kinks develop at the bending points. Finally, these hoses are only effective if they are layed on level ground for their entire length. They do not work on hilly landscapes.
Porous Drip Soakers
Porous hoses are easy to handle and are well suited to garden beds, hedges, and rows of shrubs. Porous hose systems can be difficult to install properly in lawns, even by professionals. These drip hoses are made from pressed recycled automobile tires, material that has millions of little air spaces or holes in it. These porous hoses sweat water very slowly along their entire length and are very durable. Such hoses last for 5 to 10 years if kept covered and properly cared for. They are not damaged by freezing, so they can be safely left in the garden all through the winter. For examples go to Yardener's Tool Shed and check out Soaker Hoses
Emitter Drip System
The emitter drip system is made up of a series of hoses laid throughout the garden. Each hose has little valves or nozzles (emitters) imbedded in it. These evenly spaced nozzles (12 to 20 inches apart is best), slowly release drops of water into the soil. Emitter systems are particularly good for landscapes with shrubs, such as rose bushes. The emitters can be located so that they drip right into the root zone of the shrub so that you are sure each shrub is getting sufficient water. These systems are also quite durable, but they take more maintenance than do the porous hoses. The emitters can clog up occasionally, but they are easy to replace. To reduce the chances of clogging or other damage, it is best to bring these hoses inside during the winter. For examples go to Yardener's Tool Shed and check out Drip Irrigation Kits
Microsprinklers inserted into a drip irrigation hose line produce a mist rather than droplets of water. They were developed for orchards and vineyards but are starting to turn up in backyards. This watering device is a form of drip irrigation which applies water slowly and evenly to the root zone saving water and bringing trees into bearing earlier with increased yields.
They have special advantages for the ornamental plants in your landscape. For example, the mist keeps the shallow roots of rhododendrons and azaleas cool and moist and gently refreshes the foliage and flowers. The system also protects delicate buds and flowers from frost in spring (the mist must be applied until the temperature rises to 34 degrees).
Microsprinklers are inexpensive - about 40 cost as much as one impact sprinkler. The microsprinklers can be set for varying patterns of coverage and droplet sizes.