When landscapes become too dry for your plants to thrive, it is usually because of a specific soil texture or the fault of inadequate rainfall and/or a dry climate.
Considering soil textures, an elevated sand content increases soil drainage. This ends up resulting in the loss of moisture, because water is no absorbed as much by the sand as by the surrounding soil.
Silt loam soils naturally retain water, while clay loams can alternate between being much too dry and being much too wet. Boosting landscape soils with organic material will help both the silt and loam based soils by permitting them to hold more moisture. In order to boost the soil for water retention, you must mulch around your plants with peat moss, and various types of bark and/or compost. It does not matter whether these are commercial or homemade products, both will work well. Applying this mulch just after planting shrubs and trees, to a depth of at least 2 inches, will also help to retain more water for your plants needs.
Rainfall is unpredictable, infrequent, and light in many states, particularly in the Southwest USA. Other states, including the Midwest, may have temporary periods of near-drought like condition as well. The far West US has annual forest fires that dry out the soul as well as remove dead trees from the forests. Whenever rainfall is below average, landscape plants like turf need extra water to prevent desiccation, in which the amount of water lost by a plant exceeds that absorbed by the roots. In short, the plant dries out in the heat, withers and dies. Water should be added to hydrate completely the root areas of your landscape plants; the amount depending on sizes and species of plant. At least one inch of water is needed weekly and if it fails to rain for several weeks, that amount will increase and you can call your local county extension office in order to find out how much water to add to your own specific plants. You can also find most extension offices online, listed under the local county government entities, and often in association with the agricultural department of major colleges and universities.
As an alternative option to the standard garden hose, the watering can, and the bucket brigade, there are various sizes of irrigation systems that are good for dispensing water in regions that are absolutely dry and water-challenged. A garden hose is not usually best for applying water to woody stems, because the high-pressure water from the hose can quite easily break the stems and result in large surface water run-off as well from a water flow that is much too fast. One effective irrigation system is called the drip or trickle irrigation system, and it uses the operation of a slow trickle over a longer time period in order to allow for absorption. This is good in that it replaces the strong, quick flow from water hoses that is lost before it can soak into the soil. Garden centers stock home garden irrigation systems that connect to your own outside faucet and dispense low water pressure that is much better for your plants and soil. They use plastic lines that are set among the plant and flowerbeds with an emitter placed by each large plant. An attached timer turns on the trickle and causes water to seep into the surrounding soil for a selected time period and then automatically shuts down, saving water and work, along with your plants.
Along with your new irrigation system and soil-boosting techniques, here are some sample trees and shrubs that like the more dry climates of the US, especially the Southwest and the states that experience dry soil during the summer. They will compliment your garden and help to conserve precious water.
Koelreuteria paniculata Golden-rain tree
Maclura pomifera - Osage-orange
Robinia species - Locust species
Sassafras albidum - Sassafras
Sophora japonica - Japanese pagoda tree
Ulmus pumila - Siberian elm
Berberis species - Barberry
Chaenomeles lagenaria - Flowering quince
Cytissus species - Broom species
Elaeagnus angustifolia - Russian olive
Hamamelis virginiana - Common witch-hazel
Hypericum calycinum - St. Johns Wort
Juniperus species - Juniper species
Myrica species - Bayberry species
Rhus species - Sumac species
Rosa setigera - Prairie rose
Yucca species - Adam's needle