Selection of trees depends on the desired effect and the purpose trees will satisfy in the landscape. Will they attract birds to the area? Shade a patio? Screen an unsightly view? Enhance the view of the home? Identify an entrance or exit? Trees should provide contrast and relief from surrounding buildings and create seasonal interest in areas near the home.
When selecting a specific tree consider hardiness (ability of the plant to survive extremes of winter cold and summer heat); mature height and spread; growth rate; cleanliness; type of root system; moisture and fertilizer requirements; space available; maintenance requirements; availability; ornamental effects, such as branching habit, texture, and color of bark, flower, fruit and foliage; and whether the tree is evergreen or deciduous.
Susceptibility or resistance to environmental conditions, disease and insect problems may limit your selections. A close analysis of the specific site might also help identify problems. Consider the prior use of the planting site and soil conditions, such as poor drainage, and high or low pH. The presence or absence of channelized winds and the location of utilities both above and below ground are site conditions that dictate plant choice and location. The relationship of the plant to roads, walkways and security lighting should also be considered.
The space available at the specific site and mature tree size are important considerations and addressing these limits will go a long way towards reducing maintenance costs. The planting diagram shown below represents this graphically. In no instance should trees exceeding 25 feet be planted under overhead power lines. Do not forget the underground utilities. Out-of-sight does not mean that they would not have to be serviced at some point. Permanent plantings such as trees should be spaced to allow utility service. Ground-level utility structures such as transformers and individual service connections require space to be serviced. A minimum of 10 feet is needed.
Trees can be purchased in three common forms:
1) bare-root, (BR) 2) balled and burlapped (B & B) and 3) container-grown.
Bare-root plants are normally transplanted in October or early November and again in March to mid-May. These plants may be sold with the roots tightly packed in a moisture-retaining medium that is wrapped with paper or plastic or with roots loosely covered by a moist packing medium. If bare-root trees cannot be planted soon after purchase they should be temporarily planted (heeled in) by removing the packing materials and covering the roots with soil or organic matter, such as wood chips and watered regularly to prevent drying of the root system. Bare-root trees are normally less than 21/2 inches in diameter.
Many trees are moved with a ball of soil protecting their root system.
Soil balls are heavy (approximately 100 lb./per cu.ft.). Because of the weight involved, professional landscapers or arborists who have proper equipment should be hired to plant large trees. Smaller soil balls should be carried with a hand under the ball. Carrying a balled tree by the stem or branches can result in a seriously damaged root system. Mulch and water
B & B trees thoroughly if they cannot be planted soon after purchase.
B & B trees are usually larger than bare-root trees and have a more extensive root system, often allowing for a shorter establishment time. Trees up to 8" in diameter are considered to be commercially transplantable using this method.
Many tree types are grown in containers. Advantages of this type are that the root system is undisturbed at the time of planting, and trees can be planted throughout spring, summer and fall.
Roots must be pruned immediately before planting container-grown trees. Root pruning normally leaves about 50 percent of the roots in containerized plants, which is sufficient to permit plant establishment. This compares with about 5 percent or less of the root system being transplanted with either B & B or BR plants. Always remove the container prior to planting. If container grown plants cannot be planted at the time they are purchased, place them in a sheltered location and water to keep the soil moist. Container-grown plants can be transplanted anytime when the soil temperature is 50 degrees or higher. This allows time for the plant to be established prior to the onset of winter and to avoid damage from the freezing and thawing of the soil during winter following planting.
Planting is one of the most important cultural practices that determines success or failure of tree establishment. Transplanting is not successful until the tree returns to a normal growth rate. This transplant recovery period normally takes three years, but may range from 2-8 years. To get the most satisfactory performance from trees, attention must be given to planting details. Using quality plants and following good cultural practices such as watering, pruning and fertilizing will not compensate for poor planting techniques or poor plant selection.
The usual planting seasons are spring and fall. However, container-grown trees and some B & B trees can be transplanted anytime during the growing season if proper watering practices are followed.
Community ordinances may restrict planting of trees near power lines, parking strips, street lights, sewers, traffic control signs and signals, sidewalks and property lines. Municipalities may require planting permits for trees planted on city property. City codes often require that trees on city property be maintained by the city, so citizens planting an improper selection can cause problems for themselves and the municipality.
General planting steps are as follows:
When planting bare-root, containerized and balled and burlapped trees there are several specific considerations:
Bare-root: Trees, and especially exposed roots, must be kept moist prior to planting.
Containerized: The root mass will need to be pruned to prevent circling or girdling roots.
Balled and Burlapped: Set the rootball in the hole and remove all twine and nails. Remove or loosen the burlap from the upper third of the rootball. Wire baskets should be cut and folded down so that the top of the wire is one foot below the soil surface.
Wrapping the trunks of newly planted trees can help reduce insect damage. Before applying tree wrap the trunk should be carefully inspected to ensure that there is no mechanical damage and that serious insect and disease problems are not present. Wrapping an injured tree could worsen the condition if disease or insects are present. Tree wrap should be applied from the bottom up and secured to the tree with biodegradable twine. The tree wrap should be removed within one year, normally during winter due to lower light levels at that time of year.
Guys or stakes should only be used when necessary, such as when roots are not solid in the planting hole or where the tree could be dislodged by high winds. In most instances the weight of the rootball is normally sufficient to hold the tree in place, assuming it was properly planted. Guys or stakes should be secured to the tree using a wire through a hose and attaching the guy or stake wires at that point. Normal attachment is at two-thirds the height of the tree. To avoid girdling the tree stem, guys and stakes should be removed after one year or earlier if the wire causes problems.
For at least one to two years after planting, trees should receive about 1 inch of water per week during the growing season. During hot and dry weather, supplemental irrigation is essential for tree establishment. Remember that excessive water can be as much of a problem and probably kills more plants than does a water deficiency. To help determine when watering is needed plant a drought-indicator plant in the rootball of the tree. Plants such as impatiens, coleus and ajuga wilt dramatically. If these plants are planted into the rootball of the tree, the tree can be watered whenever the indictor plant has been in shade for at least one hour and is still wilted. Mulch should be maintained for at least a year at a depth of 2 to 4 inches. In addition to helping to maintain moisture and reducing competition from weeds and grass, mulches may reduce the possibility of lawn mower damage.