Green Giant

• The Green Giant (Thuja 'Green Giant') is among the most popular choices for landscape screening. These are large trees that will grow to a maximum height of 60 feet with a 15- to 20-foot spread. Normally these plants should be place 10 to 12 feet apart, but for quick screen production 5 to 6 feet may be ideal.The Green Giant produces bright green leaves during the summer that will become darker in cool weather. It grows wider at the base and thins out at the top, and requires little pruning or care once established. Once established, the Green Giant is resistant to drought, pests and disease. The Green Giant should be planted in an area with full sun and does best in hardiness zones 5 through 7. It will adapt to just about any type of soil but prefers nutrient-rich and pH-balanced.
  
  

Leyland Cypress

• Leyland Cypress (Cupressocyparis Leylandii) is an evergreen conifer that will reach an average mature height of 50 feet. It grows fuller at the bottom and narrows at the top. Growers should plant young trees approximately 25 feet apart to produce ideal growth for a screen. These trees produce dense green needles that overlap into flat sprays. It is a hardy tree that will thrive in zones 6 through 10 and is susceptible to few pests and diseases. It does well in most kinds of soil, but requires good drainage and full sun for maximum growth. Once established, the Leyland cypress is drought-resistant and easy to care for.
  
  

Smooth Cypress

• Smooth cypress (Cupressus glabra) is a compact tree with dense foliage that makes it ideal as a landscape screen. The smooth cypress does best in zones 7 through 10 and is adapted to primarily warm weather because of its origins in the mountains of Arizona. These origins have helped the smooth cypress adapt in most soils, but it requires good drainage and a neutral or slightly acidic pH. It will reach a mature height of 30 to 50 feet with a maximum 15-foot spread. It should be planted 12 to 15 feet apart in areas with full sun, and growers should water thoroughly during the first year. Once established, the cypress will withstand drought and other environmental problems, and will be resistant to most pests and illnesses.
  
  

Hollies

• Holly has more than 600 species, making it one of the most diverse options for landscaping. There are small varieties that grow to less than half a foot, while others will reach mature heights of 60 or 70 feet. Most hollies should be planted 4 to 5 feet apart to allow room for screening. This variety makes holly ideal for adding texture, color and privacy to the yard. Most holly plants are evergreen so will keep their green foliage year-round. Holly trees should be planted in an area with partial or full sun, though some will do well with partial shade. These plants will do well throughout most of the United States as long as they are given soil that is pH-neutral or slightly acidic, well-drained and nutrient rich.