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Selecting Ornamental and Shade Trees for the Eastern Plains

Landscaping with Trees

Proper landscaping elements can conserve up to 25% of the energy needed to heat or cool a home or building. Using trees, shrubs, vines and man-made structures can modify the climate around any building to reduce heat gains in the summer and heat losses in winter. Protection from winter wind and shading from summer sunlight can effectively reduce energy consumption.

When landscaping a home, sketch it and the lot to scale, allowing 1/8 or 1/10 inch per linear foot. Identify north (N) with an arrow. On the plan, mark driveways, downspouts, utilities, fences, walkways, overhead lines and obstructions, doors, windows and other glass areas. Measure the height of the house. Observe the wind and effects of a winter storm on your building. Note the direction of winter winds, usually Northwest in origin, and add windbreaks of mostly evergreen trees to your plan to block the prevailing wind. (See Landscaping for Energy Conservation, no.7.225)

Observe the sun during different seasons of the year. Notice how the sun strikes the house in the early morning and late afternoon in the summer, and between 9 a.m. and 3 p.m. in the winter. Add deciduous shade trees to your plan to maximize summer shading and winter solar heating. Avoid planting evergreens on the south and southwest sides of a home, since they will block winter solar heat. Instead, plant evergreens on the north and west sides of your property to slow the prevailing winter winds and save on heating bills.

Choose specific trees for your plan with an understanding of their mature height and spread. The height of the structure you want to shade or protect should be considered. A single story building surrounded by medium to small trees appears aesthetically pleasing from a design perspective. Also, the mature height of trees will determine the location for maximum shading. Use small trees under utility lines and near small buildings. Remember that evergreens can provide screening from unsightly views and a sound barrier from traffic and loud noises, as well as wind protection. Keep in mind that large shade trees require large planting areas for the development of healthy root systems and a mature canopy. Avoid planting spreading trees too close to structures.

Use fences, windbreak plantings, and shade trees to provide a sun pocket on the south side of your home, creating a warm spot for outside activities during sunny, cool, but comfortable winter days. A sun pocket makes an excellent location for a patio or greenhouse.


Site Selection

Choose your planting site carefully. Match the tree's desired function to the cultural and environmental conditions of the site. These include: soil conditions and pH, available light and exposure, water and adequate drainage, localized weather patterns, terrain and elevation and the presence of a microclimate (a location with climatic conditions different from the surrounding geographic area). Choose trees that are well adapted to Colorado's harsh, variable climate. Consider that some trees are more suited to partial shade, low moisture and drought from sprinkler system malfunctions and other changes that occur as a landscape planting matures.

Choosing a Tree

Consider the normal mature height and spread of trees for your site. Trees with a slow rate of growth are generally thought to be more desirable. Fast growing trees develop weak wood that splits and breaks easily in storms, as in the snowstorm of September 1995. Consider the general shape of the tree at maturity since upright forms can be more appropriate for narrow spaces than spreading types.

Some trees are evaluated for insect and disease resistance. Crabapples, for examples, should be chosen for fire blight resistance.

Consider other plant characteristics that make trees desirable, such as flowers, fruit, fall color of leaves, winter texture in the landscape, exfoliating or colorful bark, branching habit, more than one season of ornamental interest and attractiveness to wildlife and birds.

Some characteristics make trees undesirable. Avoid planting trees with weak wood unless used for quick, temporary cover only. If fast growing, weak-wooded trees are used, plan to replace them with more suitable species as soon as possible. Add man-made structures, like arbors, to provide immediate shade. Beware of trees that are susceptible to insects and diseases or that require high maintenance and frequent pruning. Do not locate trees with excessive leaf, fruit or twig drop next to gutters, sidewalks, patios or parking lots. Avoid weedy species that become difficult to control in Colorado's environmental and social conditions, since chemical herbicides are usually the only effective controls. Never TOP trees to limit growth or control their size. Topping trees "causes decay and sprout production, resulting in a potentially hazardous situation once the sprouts become large and heavy" according to the International Society of Arboriculture, the recognized authority on tree health care.

When selecting the plant in the nursery, always choose the best, healthiest plant. Select a reputable Colorado nursery or garden center that stocks trees acclimated to our growing conditions. Nursery-grown plants are superior to "collected" plants of the same species, since containerized plants are the least risky of all, as compared to B&B stock and bare-root material. Choose only trees with good branch spacing and trunk taper. Leaves, when present, should be evenly spaced along the twigs. Avoid trees with many upright branches, rather than good horizontal growth. Do not purchase trees that have injuries to the bark or with root balls that are loose in the container, or have not been kept moist. Avoid trees with circling roots that will eventually girdle the trunk. Avoid trees with visible damage from insects or diseases.


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