There are many ways gardeners can plan and save on water usage and water requirements in the landscape.
Sometimes the old fashion methods are not used. The simplest that I know is like playing cards and gambling. Gamble and plant early. There is usually more soil moisture early in the spring than later as the average daily temperatures rise. We order some seedlings that we don't grow ourselves and have them shipped to us as early as possible. If we can't plant them outside, we heal them in and wait till they can be planted. If the seedlings are small, we consider potting them up and waiting for perfect conditions. This gives us more chances to time our plantings to the soil condtions that we want.
Old fashion methods also did not rely on lots of chemical fertilizers. Lots of fertilizers don't induce the plants to grow deep roots. Deep roots allow plants to tolerate dry periods better than shallow roots which dry out easily. Let your plants work for their nutrients. Make them develop far reaching roots and then reward them with fertilizers. These plants will not suffer as much from a lack of rainfall.
Create your own compost pile and use compost and mulches to help the soil reserve moisture. Plants are not fussy about the compost organic matter. Composted manure, leaves and grass, lawn clippings, table scraps, even Fido can contribute! Mulches hold in moisture by cutting down on evaporation of water from the soil. Mulches also help retain runoff of water when there is a hard rain. Do not use plastic liners and covers as weed barriers as these block water from the soil and also prevent air from the root zone of the plants.
Screens and buffers also help in water conservation. Screens and buffers cut down on wind velocity across the landscape. If you can buffer the winds you will help your soil retain moisture longer.
Plant selection also can be used to select plants that don't require as much moisture. An example is American Arborvitae vs Emerald Green Arborvitae. The Emerald green is more drought sensitive than the American. The emerald green is a more dense plant. Thus with more surface area, it will require more moisture making it more sensitive to drought conditions.
Use a rain barrel. My father in law uses a plastic 55 gal. drum. He fills it from the house downspouts. Water is always handy when needed and best of all its free.
If you are going to water a gentle cultivation loosens the soil so that the water can soak in easily. Hard compacted soils sends water to your neighbors. Avoid runoff, encourage the water to soak in.
