Many recommended practices for newly planted trees have changed in recent years. Here are some tips that will give newly planted trees a better chance to survive and thrive.
MULCH PROPERLY
Mulching is the most important post-planting practice that you can do to improve the health and vitality of your landscape plants. Research has shown that wood chip mulch can nearly double plant growth in the first few years after planting. Mulching conserves moisture and insulates roots from heat and cold extremes. Proper mulching provides a well-groomed appearance, eliminates grass or weed competition and prevents damage from mowers and weed trimmers. Mechanical damage is one of the leading causes of injury and death to landscape plants.
Desirable mulching materials include wood chips, wood shavings, bark or equivalent materials. Coarse-textured organic mulches are preferred since they tend to aerate the soil and replenish soil nutrients as they decompose. Mulch with a 2- to 4-inch layer of organic material. The diameter of the mulched area should be at least 2 feet, although larger areas are recommended.
Some concern has been expressed about the role mulch may play in attracting unwanted pests into the home. Termites can infest wood mulches. Never place mulch in direct contact with any wood surface on the home. Inspect mulch beds regularly if they are part of a foundation planting, especially in areas where termites are known to be a problem. If termites are detected, contact a professional pest control operator and have the structure inspected. (For more information about termites, refer to NebGuide G1062, Termites.) Mulch beds that are more than 6 feet away from the home will not cause a problem. If the home has already been treated for termites, be certain that mulch does not provide a “bridge” over the treated soil area.
Using landscape fabric for mulch in ornamental plantings is generally not recommended. Tree roots beneath landscape fabric may grow up into the fabric. If the fabric is lifted or adjusted as changes are made in the landscape, the tree roots will be damaged. In areas with a high rodent population, using landscape fabrics may increase the damage to tree roots by field mice. And unlike organic mulches, landscape fabrics do not provide nutrients to the soil. Nevertheless, in tree plantings where supplemental irrigation is not provided (such as in windbreaks), landscape fabrics may improve seedling survival by limiting weed competition and conserving soil moisture.
PRUNE SPARINGLY
Prune trees and shrubs at planting time only to remove branches damaged during handling and transplanting. Lower branches manufacture critically needed food and should not be removed. Inspect plants after a year and remove dead and crossing branches. Trees do not need to be pruned to balance the root with the top.
DON'T OVERWATER
Water is critical to the success of any tree or shrub planting. However, overwatering is a major cause of tree failure in many Nebraska communities. Heavy clay soil can severely restrict the natural percolation of water. Newly planted trees should receive no more than an inch of water a week during the growing season. Don’t water more than two or three times a week. Running automatic irrigation systems 20-30 minutes daily will severely damage the root system and can kill a tree.
WRAPPING ISN'T RECOMMENDED
For many years it was recommended that tree trunks be wrapped to protect them from sunscald or freeze injury, rodents, mowers, weed trimmers and other assorted problems. However, research has shown that tree wraps may not always protect trunks from damage and, in fact, can cause, hide and increase problems. The problems associated with tree wraps can be very damaging, so routine use of wraps is not recommended.
Wrap a tree trunk only if a nursery guarantee requires it. If the tree is susceptible to winter sunscald damage on the trunk, or during the time that the tree is being transported and needs protection from mechanical damage.
If wrapping is used, keep it on the tree only during the first winter, then remove it completely the following spring. Any wrap left on the tree during the growing season may girdle the tree as the trunk grows in diameter.
STAKING AND GUYING
The purpose of most staking and guying is to prevent the newly planted tree from tipping over in the wind. If possible, staking and guying systems should not be used, but in windy, exposed areas this practice is sometimes appropriate. Excessive movement will dislodge the small, fibrous roots from their new footing in the soil before they are firmly established. However, many trees are killed because guying materials are not removed or are improperly installed.
Staking and guying materials should be strong enough to provide support but flexible enough to allow some movement. Guying materials should have a broad surface at the point of contact with the tree to prevent damage from rubbing. Plastic horticultural tape or canvas webbing that is at least 1 1/2 inches wide are examples of good guying materials. Do not use a wire in a hose. All guying materials should be removed at the end of the first growing season to prevent trunk girdling. Any trees that do not establish within a year will more than likely never establish a strong root system. The stakes may be left in the ground, if desired, to protect the trunk from damage by mowers and other equipment.
FERTILIZING
Fertilizers are generally not recommended at planting time since most Nebraska soils contain sufficient levels of available nutrients to supply the requirements of newly planted landscape trees. Nitrogen fertilizers, in particular, should be avoided because the nitrogen promotes shoot growth over root growth, and re-establishment of the root system is required before a newly planted tree can adequately support new top growth. Sites with very poor soil or where construction activities have altered the soil composition may be deficient in certain nutrients. In such cases, professional help should be sought.