Getting Established

• New trees should be planted in the spring or fall.Martin Poole/Digital Vision/Getty Images
  
  Newly planted trees need at least one year, more often two or even three years, to expand their root system into the soil in the new location, or to become established. Even highly drought tolerant trees are not drought tolerant during this time and need supplemental water.
  
  How much water is needed and how often it is needed varies. Check the soil at half the depth of the planting hole right next to the roots or root ball. Gently dig a small hole just big enough to reach in and grab a handful of soil three to four hours after watering. The dirt should be moist enough to stick together when squeezed, but not so soggy that it drips.
  
  

Soil Conditions

• Soil can be organically rich, nutrient poor or somewhere in between.Jupiterimages/Photos.com/Getty Images
  
  The degree of drought resistance a tree has can be affected by soil conditions. Many types of trees are highly adaptable to most types of soil, but many are not. Soil is generally sandy, loamy or clay in texture. Trees that naturally thrive in sandy soil are unlikely to grow well in heavy clay, while those that thrive in clay or loamy soil may struggle in sandy soil. The right soil conditions will result in a stronger healthier fast growing tree that is better able to withstand drought.
  
  

Deciduous Trees

• Silver maples are less drought tolerant where their root growth is restricted.Medioimages/Photodisc/Photodisc/Getty Images
  
  Deciduous trees lose their leaves each winter. Silver maples (Acer saccharinum) are very fast-growing deciduous trees that are winter hardy in USDA Hardiness Zones 3A through 9B.
  
  These trees are highly drought tolerant when they are planted where their roots can grow unabated. The soil can be sandy, loamy or clay, but silver maples do best in soil with an acidic pH. The mature height of a silver maple is between 60 and 80 feet.
  
  The 'Shademaster' thornless honeylocust tree (Gleditsia triacanthos var. inermis) grows between 2 and 4 feet per year for the first 15 years with a mature height of 50 to 70 feet. It is a deciduous tree with the added benefit of having narrow one-half inch to 2-inch long leaflets that disappear into the grass in the fall. This tree is hardy in USDA hardiness Zones 5A through 8A and is highly drought tolerant with no specific soil preference.
  
  

Evergreen Trees

• Evergreen trees retain their foliage year round. Burk eastern red cedar (Juniperus virginiana 'Burkii') is a fast growing evergreen with a mature height of 15 to 25 feet. This is a highly drought tolerant tree that is hardy in USDA Hardiness Zones 3A through 9B. It will grow in any type of soil.
  
  Glauca Blue Atlas Cedar (Cedrus atlantica) is an evergreen that grows quickly while young, then slows down as it ages. With a mature height of 40 to 60 feet and width of 25 to 40 feet, it is well suited to a large open planting site. This tree is hardy in planting Zones 6A through 8B and is highly drought tolerant. It will grow in any type of soil with an acidic to slightly alkaline pH.