Short Boxwoods

• Short boxwoods can also be planted and trimmed as a very low hedge-type flowerbed border.Medioimages/Photodisc/Valueline/Getty Images
  
  Short boxwood varieties are commonly used as accent or foundation shrubs but they can be planted as low hedges. Buxus "Green Gem" grows to a height and width of 1 1/2 to 2 feet. It is hardy in USDA hardiness zones 4 to 9. B. "Green Mound" grows to between 2 and 3 feet tall and wide in 10 years but can mature to between 4 and 5 feet. B. sempervirens "Saint Genevieve" grows quickly to a height of 2 to 4 feet and width of 3 to 5 feet. It can eventually grow to 7 feet tall and 9 feet wide but it generally takes 25 years to reach that size. Green Mound and Saint Genevieve are hardy in zones 5 to 8.
  
  

Shorter Mid-Sized Boxwoods

• "Helleri" is a yellow-leaved cultivar that grows to a height of 4 feet.Jupiterimages/Photos.com/Getty Images
  
  Shorter mid-sized boxwoods are commonly planted as a low hedge but can also be used as foundation shrubs. B. sempervirens "Aurea Pendula" is hardy in zones 6 to 9. It grows to a mature height and width of 4 to 6 feet with an open weeping form. The foliage is medium to dark bluish green with yellow variegation. B. sempervirens "Elegantissima" is hardy in zones 6 to 8 and grows in a compact mounding form to a height of 3 to 5 feet. Its foliage is medium green with cream edges. B. "Green Mountain" is hardy in zones 5 to 9. It grows to a mature height of 3 to 5 feet and width of 2 to 3 feet with medium green foliage.
  
  

Taller Mid-Sized Boxwoods

• Boxwoods are often used in topiary.Jupiterimages/Photos.com/Getty Images
  
  Taller mid-sized boxwoods are most commonly planted as a hedge. B. sempervirens "Edgar Anderson" grows to a height of 5 to 6 feet with a width of 4 to 5 feet. B. sempervirens "Rochester" grows to a mature height of 4 to 7 feet and width of 3 to 5 feet. Edgar Anderson and Rochester are hardy in zones 6 to 8. B. sempervirens "Pullman" grows to between 4 and 7 feet tall with a width of 2 to 4 feet. It is hardy to zone 5.
  
  

Tall Boxwoods

• Tall boxwoods are often planted at the end of a hedge or on either side of a doorway or pathway. B. sempervirens "Fastigiata" is hardy in zones 6 to 8. It is a tall column shaped boxwood that grows to a mature height of 10 to 12 feet with a width of only 4 to 5 feet. B. microphylla var. japonica "National" is another tall boxwood that can grow to a mature height of 12 feet tall. This one becomes as wide as it is tall, however. National can be used as a tall hedge or pruned to stay more narrow. It is hardy in zones 6 to 9.