Using Landscaping Trees and Shrubs
Trees and shrubs are the foundation of most landscape plantings. In order to select the right plants for your landscape area, there are several factors to consider. These factors will influence the choice, and subsequent health, of plants for your landscape area.
Area of Landscape and Function of Planting
Before considering specific landscape plants, evaluate the area for which you are planting. The word “landscape” can conjure many things to many people. Generally, landscape in this article refers to an area that frames a building, roadway, or public space, and is designed to be attractive and fairly low-maintenance. Here are some areas for which a formally designed landscape is appropriate, and enhances the location:
• Interstate exits
• Commercial buildings (offices, shopping malls)
• Resorts and hotels
• Parks-municipal and amusement parks
• Around pools
• City right-of-ways
Each of the above locations presents its own challenges and opportunities. An interstate exit area might not be the first place you would look for beauty, but some states put significant funding into roadside beautification. In North Carolina, many of the exits are landscaped with swaths of Crape myrtles, daylilies, canna, junipers, pear trees, wildflowers, and other blooming and/or evergreen plants. Research has shown that these blocks of colors help keep drivers alert. For homeowners on a cross-state drive, the exits present the chance to see plants that do well under extreme conditions. Something that survives with minimal input on the side of a highway is generally bound to do well with more care. These locations also showcase plants that look great in massed plantings.
Parks usually have a lot of foot traffic. That can lead to compaction problems for the plants. City planners and homeowners who spend most of their free time in their back yards can get ideas from healthy-looking trees in well-traveled sections of park landscapes.
Landscapes around homes can serve different functions. A planting along the property line could serve as a privacy screen. Large shade trees might be desirable for outdoor living areas. Landscape beds closer to a house or building benefit from the form and structure of trees and shrubs, but do not have room, usually, for larger trees. Smaller trees such as dogwood, redbud, and serviceberry do well in these locations.
The location and function of landscape beds are important factors in plant selection.
Another set of factors that will influence the selection of trees and shrubs for your landscape are the growing conditions in the area you will plant. Evaluate the following before selecting plants:
• Light-is the area sunny or shady
• Water-is there irrigation, standing water, or fast-draining soil?
• Soil-type- is there ample compost or organic matter? Is the soil heavy clay, or light sand?
• pH-is the soil pH acidic (below 6) neutral (6-7.5) or alkaline (above 7.5)
You can try growing plants in conditions that they are not naturally suited to, but they will require much more maintenance, and still will not grow as well as plants selected specifically for the natural growing conditions available.
Hard-working Trees and Shrubs for the Landscape
The plants selected and detailed below were selected because they do well with little maintenance, and are drought, heat, and/or wind-resistant. Their natural growing habits are desirable in landscapes, and they are easily found in the nursery trade.
The landscape trees detailed below are suitable for a wide range of growing conditions. Some grow to be quite large and are best for big yards, or large commercial properties. Many are under-used, but still available.
River birches are resistant to birch borer, and grow well in zones 4-7 in moist soils. They are most attractive when pruned as multi-stemmed trees with three or five trunks.
Native to the coastal and gulf regions of the south, live oaks thrive in zones 7-10. Their wood is dense and was once used extensively in ship-building. They have a slow, spreading growth habit. Many native areas of live oaks have been cut down for development. Planting one in your yard is a contribution to the future of your neighborhood. Developments that can spare the money to plant live oaks will help restore the population of this tree, and provide centuries of shade and animal habitat.
The American beech is the best species for North America, but is not available in cultivation, for the most part. These trees grow slowly, but have beautiful, smooth, gray bark. The fall color can be spectacular. It grows best in zones 4-7 in full sun to part shade.
Redbuds are native to the eastern United States, and grow along the edges of forests. They are small trees, perfect for landscape beds close to the house. Their umbrella-shaped canopy is a nice, and somewhat unusual shape in the landscape. It provides dense shade during the summer, great for shade perennial gardens. The flowers in spring, nice leaf texture during summer, and fall color makes this a great landscape tree.
Red maples are universally beloved for their fall color. There are hundreds of cultivars available for this tree, which is one of the first deciduous trees to bloom in the spring. If you drive along the highways during the early spring, the reddish, misty sheen to the forest is generally caused by red maples in bloom. Their tiny, finger-nail sized flowers are small and unobtrusive on an individual basis, but do provide a bit of color in the spring.
Some trees have less desirable habits that outweigh their good attributes. Some people would prefer not to plant sweet gum trees because their fruits (balls a little smaller than a ping-pong ball, with hooks on them) can be messy. However, if you need a large tree and you want pretty fall color, sweet gums are a must. They turn multiple shades of color-from purple to red to yellow to orange-in the fall. You can find non-fruiting sweet gums at some nurseries.
The genus Tilia has several species of linden trees. These trees are under-used in the landscape, but they are hard to beat, in terms of color and form. They generally have strong pyramidal forms and are striking from a distance. Even the littleleaf linden, Tilia cordata, grows to be fairly large, so these trees are better for larger yards. They are a good substitute for elm trees and Bradford pears (though, they do grow larger than pears), because they have stronger wood and better branch angles, and thus are less prone to storm damage.
Photo courtesy of taliesin at morguefile.com.
There are many species and cultivars of viburnum, which grow in virtually every growing zone in the United States. Some evergreen varieties grow in the south, but more popular varieties include the arrowwood and Korean spice viburnum. Both have sweetly scented flowers and a nice growth habit. They grow well in full sun to part shade.
A species rose, the Rosa rugosa, is pretty in masses, and makes a good barrier to keeping people, pets and animals out of a particular area. They grow well in all conditions, and are wind and salt-tolerant. They can be renewal-pruned or sheared down to the ground and will re-grow quickly. In the fall, their fruits turn bright red and attract birds. Often, their leaves have fall color as well.
One of the most gorgeous, large shrubs/small trees available, the Bottlebrush Buckeye, Aesculus parviflora, is hardy in zones 4-8. It can grow to be about 12 feet tall, and also spreads horizontally. It has tall, white, foamy-looking flower spikes in the early summer, which is where the “bottlebrush” name comes from. It grows best in moist, well-drained, acidic soil in part shade to full sun. In the fall, the leaves turn a brilliant yellow.
Native species and cultivars of this small tree/shrub populate most of the United States. It provides three season interest with flowers, fruit and red fall color. The small size makes this tree a good choice for landscape beds close to the house or other structures.
The Encore azaleas are a trademarked, re-blooming azalea that will set you back a few more dollars than regular Formosa azaleas. The upside is that Encores reliably re-bloom twice or three times during the year. They are relatively new on the market, so their eventual growing height isn’t widely published. They prefer acidic soils in full shade. They will grow in partial sun, but will not bloom as frequently.
Every home in the southern US should have some Sasanqua camellias. This variety blooms earlier than the traditional Japonica, and also grows more quickly and larger. They grow best in full shade to part sun, and their evergreen, broad-leafed foliage adds color to the landscape bed during winter.
Commonly known as sweetshrub or spicebush, this shrub has smooth, medium-green leaves and maroon flowers that look like miniature magnolia blooms. The flowers and leaves have a spicy scent. It grows best in shade, but will tolerate shade.
Crape myrtles are used widely in landscapes large and small throughout the south. It can be grown as a multi-stemmed or single stemmed tree, or as a shrub. Dwarf cultivars function more as shrubs. It blooms in the late summer when many other plants have gone into a semi-dormancy because of the heath. When pruning crape myrtles in the winter, only remove branches smaller than your index finger. You can pollard them (cut them all the way back to the main branches, but they aren’t as attractive that way.)
There are hundreds of trees and shrubs that work well in the landscape. The above list is just a start, but a good place to start for reliable, easy to grow trees and shrubs.
Manual of Woodly Landscape Plants by Michael A. Dirr