Shrubs for Colorado Landscapes - CSU Extension in El Paso County
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Shrubs for Colorado Landscapes - CSU Extension in El Paso County
Year Round Gardening Shrubs for Colorado Landscapes Barbara Bates, Colorado State University Extension Natural landscapes are comprised of layers of plants: low groundcovers and herbaceous plants, a middle layer of shrubs, small trees and finally a canopy of mature taller trees. The middle layer of shrubs ranges from about 5 to 15 ft. It is the layer that is most in scale with the human form, and the layer people can most easily notice, interact with and use for various purposes in the landscape. A general definition of shrubs is that they are multistem woody plants, either deciduous or evergreen. In the home landscape they can be used as borders, screens, focal points, habitat for birds, berry and nut producers and for scent, bloom and fall color. As with most plants, it is critical to choose the right plant for the right purpose and place. Over their lifetime, shrubs require much less care than perennial flowers that require division and annual clean up, yet shrubs can offer bloom, interesting foliage and fruits to delight both people and wildlife. Some shrubs will require more cultural attention, while others are relatively carefree. For the north side of your home, try members of the viburnum family for bloom, fragrance and colorful berries. Wayfaring tree (Viburnum lantana) is a large shrub that is coarse in texture and form. It is best used as a background planting for smaller shrubs or perennials, or as a border and screening plant. Flower clusters bloom in spring, followed by clusters of berries that transition from yellow to red to black as the season passes. For a specimen shrub that is evergreen, consider the globe arborvitaes (Thuga occidentalis). Knowing the mature size of these slow growing cultivars will help you make the right selection. “Hetz Midget” is the smallest at 3 ft., then “Little Giant” at 4ft, and “Holmstrup” at 5ft. It is important to get the proper cultivar for the desired mature height. You can plant a variety of cultivars to create a whimsical grouping. For southern exposures, Mountain mahogany (Cercocarpus) and New Mexico privet (Forestiera neomexicana) are choices that will not require much care beyond the initial years of establishment. Both are about 10 ft. tall when mature, making them good candidates for shading a patio and providing screening. Both are xeric plants, with small leaves. New Mexico privet has silvery gray stems that provide winter interest. Curly Leaf Mountain mahogany (C. ledifolius) has distinctive feathery seed heads and evergreen leaves. Red elder (Sambucus racemosa) is a smaller shrub for southern exposures. The shiny leaves and clusters of creamy flowers make this one stand out in summer landscapes. Bright red berries in fall can attract birds. This plant will be happiest planted in low spots or near a downspout where it will get seem additional water. If you have an area that is difficult to mow or a steep slope and you need a woody filler plant, consider Snowberry (Symphoricarpus albus) and its close cousin Coralberry (S. orbiculatus). The names indicate the color of the fruit. It is low, about 3 ft., with arching branches lined with small round leaves. This native plant spreads by underground runners and once established, requires little care. Both these species are shade tolerant and can be used under existing trees. If you are looking for an evergreen groundcover I recommend Compact Andorra junipers (Juniperus “Andorra Compactus). This plant stays under 2 ft. but spreads to 5ft. The foliage color changes with each season: bright green in spring, blue-green in summer, bronze in fall followed by plum tones in winter. Mass plantings of Andorras on slopes used as groundcovers are very low maintenance and visually appealing. For more information on Native Shrubs for Colorado refer to Fact Sheet 7.422 at http://www.ext.colostate.edu/pubs/garden/07422.html Plan to attend some or all of the weekly Spring Garden Classes sponsored by CSU Extension. Classes start on March 21 and continue through May 19th. Each class is held on Saturday morning at DeVry University and repeated on Tuesday afternoon at the Extension office. For more information go to the CSU website at http://elpasoco.colostate.edu/. When you have questions, Colorado State University Extension has research based answers Get answers to your horticulture questions by calling a Master Gardener Volunteer at 520-7684 or visiting https://ask.extension.org Colorado State University, U.S. Department of Agriculture and El Paso County Extension Programs are available to all without discrimination