The gardener who can do a thorough job of watering with hose in hand is rare indeed.
Assuming that the hose spews out about 3 gallons per minute in a circle about 4 feet in diameter, I roughly calculate that said gardener would have to stand immobile for more than two minutes before moving on to the next 4-foot-in-diameter circle of thirsty plants.
A sprinkler is one obvious solution.
Even better is “drip irrigation,” a method of applying water to plants slowly and over an extended period of time. Drip irrigation has many benefits, not the least of which is cutting down water use by about 60 percent. That water savings comes from less evaporation and less waste; water isn’t wasted watering in paths or between widely spaced plants. So there’s also less weed growth. Garden plants grow better because they’re never thirsty, and dry leaves means less disease.
A primitive drip irrigation system can be cobbled together by running water through an old garden hose that’s riddled with holes along its length and has its end plugged. The problem is that less water drips from the holes at the end than from the ones at the beginning, and higher ground would get less water than lower ground.
A drip irrigation system that you buy has water emitters engineered to offer a consistent, specified output over wide changes in elevation and pressure. They’re also made to be resistant to clogging or root penetration.
Emitters, those that you plug in or those pre-installed, typically put out water at a specified, leisurely rate of 1/4 to 4 gallons per hour.
Right at the hose spigot is the best part of a drip irrigation system: the battery-operated timer. This timer automatically turns the water on and off, and at about the rate that garden plants are using water.
Of course, water use depends on the weather and the size and kind of plants, but a half hour of dripping per day is usually about right. That may seem like a lot of water, but remember, the water is just dripping. If a timer can turn the water on and off three times a day, set it for three 10-minute waterings; if six times a day, set it for six 5-minute waterings; etc.
The timer brings an important benefit of drip irrigation: It saves time. Rather than standing frozen in your garden with a hose, you become free to do other things. Like smelling the flowers.