Large fast-growing shrubs can assist you in providing shade for areas in your yard. Select plants that grow in full sun or partial shade and are fairly hardy once established. Some are evergreen while others may drop some foliage during winter in cold growing zones. Choose shrubs well suited to your landscape and growing zone to create a successful, well-shaded area.
Italian cypress (Cupressus sempervirens 'Glauca') grows well in full sun and well drained soil, according to the University of Florida. These evergreen shrubs are best suited to growing zones in the southern and west coast portions of the United States incorporating USDA growing zones 7B through 11. Under optimal conditions, these shrubs grow quickly, up to 3 feet in a year. The height of a fully mature shrub can be 25 to 40 feet. Since the shrub is narrow, at most 3 feet across at the widest portion, several can provide a large shaded area when planted side by side, creating a screen effect. Plant shrubs 3 to 6 feet apart, depending on the density of the shade screen desired.
These column-shaped trees are fairly hardy and need minimal care, but they can be damaged by bag worms and incorrect watering practices. Most grow to the maximum 40-foot height in wide open spaces where roots are not blocked by other plants or obstacles. Those planted in residential areas tend to top out on average at 20 to 25 feet.
Rose of Sharon, Shrub Althea
The althaea or rose of Sharon (Hibiscus syriacus) shrub is native to China and India. According to the University of Illinois Extension, it grows quickly and tops out at 8 to 12 feet tall and 6 to 10 feet wide, making it more than able to shade the area around it. The shrub grows well in USDA zones 5 through 8 and features green foliage and large red, white, purple or pink single and double flowers in late summer. When purchasing a rose of Sharon, choose the variety based on the colour and shape of the flower. Althea grows well in areas of full sun or partial shade and should be planted in well draining soil. It easily tolerates wind and alkaline soils. Use the rose of Sharon as a hedge plant, individual specimen or as a border. Trimming and shaping are not necessary but are tolerated by the shrub. Annual trimming in early spring encourages more flowers in late summer. While fairly hardy, the rose of Sharon can attract Japanese beetles, whiteflies and aphids. It can also harbour grey mould and powdery mildew.
Bamboo is one of the fastest growing of the shade-producing shrubs but can also be invasive. It is a dense evergreen producing columns of 6- to 20-foot tall shoots. According to Texas A&M University, bamboo often dies off in cold climates but quickly regenerates and grows back to a shade-producing height in the spring. Bamboo is hardy and can be planted as a natural screen shade plant, barrier or background for other garden plants. It can also be harvested and used for a multitude of craft and building purposes.
Bamboo (Bambusa) grows in sun and partial shade and can be successfully grown throughout the United States, gaining full height and density in areas with warmer weather. Due to the extremely invasive root system, plant bamboo using a commercially available rhizome barrier.
- University of Florida IFAS Extension: ENH385/ST226: Cupressus sempervirens 'Glauca': 'Glauca' Italian Cypress
- University of Illinois Extension: Rose of Sharon, Shrub Althea (Hybiscus syriacus) - Selecting Shrubs for Your Home: University of Illinois Extension
- Texas A&M University Aggie Horticulture: Large Shrubs