Pruning large shrubs yearly removes dead limbs and encourages new growth.
Small shrubs are often used in home landscapes, mixed beds and along foundations. Large shrubs also serve their purpose. Large shrubs are those larger than 8 feet high, although the tallest shrubs may grow 20 to 50 feet high. Plant tall shrubs as hedges, privacy screens or wind breaks. Avoid planting them near entryways or windows.
Arborvitaes
Arborvitaes (Thuja occidentalis) may be classified as trees, although they don't have a visible trunk. These evergreen shrubs are inexpensive and adapt to various growing conditions. They may have a pyramidal or rounded form and foliage color varies from bright green, gray-blue to yellow. The largest varieties grow 50 feet or more, while dwarf varieties stay less than 3 feet high. Techny and Pyramidalis are two of the most common tall varieties, with dark-green foliage and a pyramid shape.
Spreading Shrubs
Gambel oaks, sumacs and pussywillows are native shrubs that often grow in colonies, spreading and covering large areas. These plants grow 10 to 25 feet high, depending on conditions and species. They are best reserved for natural areas for soil erosion prevention or windbreaks.
Tall Deciduous Shrubs
For a home landscape, try Snowball Bush viburnum, double-file viburnum, or Linden viburnum, which grow between 9 and 15 feet high. Common lilacs grow 20 feet high and are hardy to U.S. Department of Agriculture plant hardiness zone 3. Their cousin, the Japanese tree lilac, while technically a tree, resembles a shrub when allowed to take its naturally bushy form. It grows 30 feet high and produces creamy flowers. Burning bush and butterfly bush vary widely in their final height, depending on growing conditions. In areas with cold winters, they rarely grow taller than 6 feet. In warm, mild regions, the plants may grow to 12 feet high and become invasive.
Considerations
Consider how wide a plant grows, as well as how tall when selecting large shrubs. Allow plenty of room for the shrub's mature size, as most shrubs don't tolerate severe pruning. Select shrubs adapted to the local climate and are disease resistant. For a windbreak, intermix evergreens with deciduous shrubs.
