Mature Tree Care

A Mature Tree is not replaceable within our children’s lifetime.

Mature trees create a living third dimension to our surroundings that can grow taller than the home that we inhabit and become older than anyone that ever lived. Very often we take them for granted because they have been here so long and we don’t appreciate their value until they are gone.

Most mature trees are not a renewable resource within our lifetime. A large hardwood tree can easily live to be 200 to 300 years old. The standard rate of growth for most oak trees is five to six years per diameter inch of trunk diameter. This means that a twenty-four-inch diameter oak tree, which may seem common now, is not replaceable within our children’s lifetime.

Mature trees appear indestructible because we only see the toughest half of the tree that is above the ground. This upper portion of the tree system has developed over millennia to withstand the severe weather and environmental conditions in its natural habitat. It is important to understand that the part of the tree above the ground is actually the most resilient portion of the tree system. We sometimes believe that if our mature trees appear in good health above the ground then everything is OK overall. However, the most sensitive portion of a mature tree is the root system.

Roots have a very low tolerance to changes in soil conditions. They grow into areas of soil that have a specific range of air content, moisture content, compaction, and nutrient availability. If these conditions change then the roots cannot adjust, so they die and decay. The process of soil/root-related tree decline may be slow, but the process can become irreversible long before the tree dies or falls over. Advancements in the science of arboriculture now allow us to better understand the physiology of tree development and the dynamics of tree reactions to environmental conditions. The old practice of topping and fertilizing a declining mature tree has killed many more trees than it helped. Fertilization with high nitrogen lawn fertilizers and over-watering can actually deteriorate the root system of a mature tree and make it dependant on a superficial root system that cannot tolerate drought conditions and may not be able to support the tree in high wind storms. It is more important to maintain a deep root system and develop a microbial and biological balance in the soil than to add nitrogen to the soil that will turn the leaves greener like the grass.


Our Mature Tree Program

Our Mature Tree Program is based on the belief that a tree will grow well and live a long life when most of the environmental conditions are correct and the physical limiting factors are minimized. Each species has its own characteristics and every tree has its individual structure and condition. We treat each tree according to its individual requirements for healthy growth and long-term development.

Evaluating and understanding the actual condition and physical limiting factors of a mature tree may require assessing the visual characteristics, diagnostic testing, soil or tissue analysis, and monitoring the condition of the tree through several seasons. Our program is developed to maximize the aboveground and belowground environmental conditions that affect your trees to meet the tree’s need for optimum growth and longevity.

Actual treatments may involve prescription fertilization, biostimulant inoculation, soil modification, insect and disease control, site modification, and tree growth hormone modification.


Construction Damage

Many homes are constructed in the midst of wooded areas to take advantage of the aesthetic and environmental value of the native forest. The mature trees add a different dimension to the new house and create a landscape that appears natural and robust. Unfortunately, many of these mature trees are severely damaged during the construction of the house. Homeowners may be heartbroken when they learn that their once beautiful trees are dying and will need to be removed.

The ideal solution is to prevent the damage from construction before it occurs. Arbor Care Resources can produce a Tree Preservation Plan that can be incorporated into both the planning and construction phases of development to avoid damaging key mature trees on the property. A fundamental aspect of this plan is a preliminary assessment of the trees being considered to determine their viability for preservation. Utility plans, landscape plans, grade changes, site improvements, and changes in the water table all need to be considered when developing a preservation plan for the mature trees. An effective plan can only be developed by someone with knowledge of arboriculture and experience in both tree preservation and construction. The common method of trying to preserve mature trees on a site by just not hitting the trunk of the tree with the backhoe is one of the reasons that so many mature trees die on new construction sites.

Trees are injured during a construction process when the trunk of the tree is wounded by construction equipment, the water table is lowered by changes in topography, or the root system is damaged. The most common cause of tree decline and failure is damage to the root system. This occurs when the soil containing the root system of the tree is graded off, buried, dug up to bury utility lines, or compacted by construction equipment driving over it. Symptoms of construction damage may include smaller and fewer leaves, dieback in the crown of the tree, and premature leaf drop. Because most trees have a high level of stored energy reserves, a tree with a fatally injured root system may decline slowly over several years and die long after the contractor has left the property.

The process of reducing the impact of construction damage and improving the vitality of a mature tree can be more expensive than removing the tree and planting a new one. A mature tree may still die from damage to the root system regardless of the remedial treatment provided. The treatment process requires a complete assessment of both the tree and the surrounding root zone, consultation, and a decision on how important the tree is within the landscape to determine the scope of the remedial treatment.

Arbor Care Resources has a complete remedial treatment program for trees damaged from construction. Remedial treatments for trees damaged by construction can include pruning, soil modification, and radial trench mulching, prescription fertilization, and treatment with tree growth regulators. Pruning may be necessary to reduce the hazard potential of the tee or correct a structural defect. Soil modification or radial trenching may be needed to reduce the compaction of the soil so air and water can percolate through. Treatment with tree growth regulators can alter the development of the tree to reduce canopy development and increase root growth. Proper watering, mulching, and fertilization are also very important. 

Drought Stress Damage

Drought has a long-term effect on mature trees. 2002 was the 3rd year of severe rain shortfall. Unlike grass, small shrubs or young established trees, mature trees take several years to recover. The effects of severe drought stress can begin a decline in the mature trees that can continue even after soil moisture conditions improve. The effects of this decline are not obvious until the tree begins to die. The later stages of this decline may be irreversible.

During severe drought periods, the small root hairs responsible for nutrient and water uptake die. The ability to take up available water and nutrients is reduced. The tree has to use stored energy reserves to replace them. If the drought is severe, as our recent drought has been, the woody roots begin to die. This not only causes a severe loss of nutrient absorption ability, but the roots become susceptible to opportunistic diseases and decay fungus that can travel through the drought-stressed root system quickly.

Depending on the severity and species, the solution may be to remove the declining trees and replant with more drought-tolerant varieties.

Arbor Care Resources management strategies for drought Stress reduction include: Determining which trees are severely stressed and which trees are most important within the landscape, Watering with at least 1 inch of water throughout the root zone of the tree one time a week when no precipitation has occurred, Mulching with at least 2 inches of mulch over as much of the root system as possible, Removing the grass (which competes with the tree roots) from under the tree canopy and replacing it with mulch, Fertilization according to a soil analysis or with a low salt, slow-release nitrogen fertilizer, Incorporation of organic biostimulants and Mycorrhizae to help stimulate new root development, Preventing or treating insect and disease problems.

Tree Growth Regulators can be used on key trees to reverse the effects of drought stress and minor tree decline.


Buried Root Collar Damage

Planting a tree too deep, burying the trunk and root collar, having more than four inches of mulch over the root zone, or making a mound of mulch around the trunk of a tree can needlessly stress and often kill a healthy tree.

The root collar (the base of the trunk and root flair) and the trunk have a different outer tissue than the roots. Roots have evolved many mechanisms to survive in continually moist environments while the trunks of most woody plants have not. Constant moisture on the bark can reduce the respiration in the bark tissue, which will slow down the sap flow for the entire tree. The moist tissue also becomes more susceptible to several serious diseases.

Arbor Care Resources can perform a root collar excavation to remove the soil and mulch from the root collar and trunk. If the root collar is below the soil line then the hole can be welled or filled with drainage stone. Over mulching is also a serious problem in landscape beds. More than four inches of mulch can reduce the oxygen in the soil, create a waterlogging effect, and force the tree to develop a surface root system that is susceptible to drought damage or uprooting.

Radial Trench Mulching

A silent killer and the cause of many tree problems is soil compaction. Construction, re-landscaping, or even heavy foot traffic can collapse air passages and compact soils, thereby reducing their porosity (A simple test for soil compaction is to try to push a pencil into the soil. If you can’t push a pencil through it, roots can’t grow in it!). Without sufficient oxygen and water the entire soil system slows down and trees will begin to decline. These trees may become nutrient deficient, not for lack of elements in the soil but because important micro-organisms have been disturbed which would normally facilitate the absorption of these elements into the tree. Likewise, the addition of fertilizers may be of little or no benefit to the soil or the tree.

One of the methods we use for soil modification is Radial Trench Mulching. This is a process of using a supersonic air excavator to dig trenches throughout the root zone of the tree without cutting the roots. These trenches are then filled with soil, organic material, and biological stimulants. The soil is modified to allow for optimum root development of a particular species of tree and the existing growing conditions. This method of treatment has been proven to be one of the most effective methods of soil modification for compacted soils over tree roots.


Insect and Disease Control

Arbor Care Resources specializes in insect and disease identification, plant tolerance and impact assessment, and insect and disease control. We track the level of development of most of the problem pests in Southern New Jersey and monitor the temperature, moisture, and growing degree days on a weekly basis. We stay abreast of the latest developments in control measures that are suitable for our area.

Several factors affect the level of insect and disease infestation from year to year. These factors are interrelated and will always vary. While some pests are always a problem, most insects and diseases fluctuate in severity from year to year or are dependent upon specific weather conditions. The impact of all pathogens is directly related to the vitality of the tree and its ability to resist infection or recover from the damage caused.

Insect and disease control is accomplished in our Integrated Pest Management program by improving the vitality of the plants, increasing the environmental conditions for the development of beneficial insects, and reducing the environmental conditions that are favorable for the development of pest insects and diseases. Choosing the right plant for the right location, proper irrigation and drainage, mulching, pruning, and removal of diseased or severely infested plants are all part of a good pest management program. Pesticide applications are made to keep insects and diseases below an acceptable threshold. Pesticides of the lowest toxicity and the highest effectiveness are used during the most sensitive stage of the life cycle. All applications are made according to the latest research and recommendations in the industry. All applications will be made by trained and licensed operators and in accordance with all regulations of the New Jersey Department of Environmental Protection.

Soil Modification

Soil is a natural complex of organic minerals, inorganic minerals, air, water, and living organisms supplying nutrients, moisture, and anchorage for plants. All these components are of equal value in the function of a good living soil. The soil must contain living organisms along with minerals, air, and water. The living organisms in the soil have specific functions and although microscopic, they are essential to plant life. The soil must have oxygen and the oxygen is moved through the soil by the water. This is a very balanced and fragile system that must be protected to allow for healthy tree growth.

Undisturbed soil is not a solid mass. A well-drained soil is composed of fifty percent air space and half of that is taken up by water when available. Undisturbed forest soil usually has an oxygen concentration of 16-22 percent (22 percent is the concentration in the atmosphere). Roots and microorganisms grow and thrive within this soil system and the need for additional treatment or modification is minimal.

A silent killer and the cause of many problems is soil compaction. Construction, re-landscaping, or even heavy foot traffic can collapse air passages and compact soils, thereby reducing their porosity (A simple test is to try to push a pencil into the soil. If you can’t push a pencil through it, roots can’t grow in it!). Without sufficient oxygen and water the entire soil system slows down and trees will begin to decline. These trees may become nutrient deficient, not for lack of elements in the soil but important micro-organisms have been disturbed which would normally facilitate the absorption of these elements into the tree. Likewise, the addition of fertilizers may be of little or no benefit to the soil or the tree.

Some of Arbor Care Resources’ soil treatments involve radial trench mulching, soil replacement, soil injections of biostimulants, and treatment with organic materials containing live microorganisms.


Hazardous Tree Assessment

Arbor Care Resources performs both Hazardous Tree Assessments on specific trees and training seminars for Hazardous Tree Assessment for tree industry organizations or shade tree commissions.

It is very obvious after a tree falls and causes damage that it was hazardous before it fell. The purpose of determining the hazard potential of a tree is usually to determine the hazard before it occurs. Determining the Hazard Rating or recognizing a potential hazard can be done using several scientific methods, different rules of thumb, or just experience and common sense. The recognition of the hazard is relative to who is making the observation.

A measurement of how observable a pre-existing defect is in a tree will always be relative to who is making the observation. While it is usually not possible to guarantee that every defect in a tree has been identified, an experienced arborist with proper training can recognize most potentially hazardous conditions during a hazardous tree evaluation.

The process most often used for determining the hazard potential is from the International Society of Arboriculture Photographic Guide to the Evaluation of Hazard Trees in Urban Areas, 2nd edition. This guide is generally considered the standard in the tree care industry for tree hazard determination.

While the process for determining the hazard rating is based on many quantitative characteristics that relate to the structural stability of the tree, it is not possible to guarantee the safety or hazard of any tree, calculate unseen characteristics, or predict environmental factors that may impact the hazard of the tree. A hazard rating does not define “danger” or determine when a tree becomes “dangerous”. The level of acceptable or unacceptable risk associated with the potential for tree hazards are better determined by those directly affected by them. Some level of risk will always be present when people live among trees. The decision of how much risk is tolerable remains with the owner or manager.

The rating method that we normally use to evaluate the hazard potential is a 12 point rating divided into three categories: size, failure potential, and target. A higher score indicates a higher hazard potential. Determining the rating for the size of the tree and the rating for the target area can be determined accurately from measurements and observation of the target area. However, many factors must be considered when determining the failure potential rating.

The Photographic Guide to the Evaluation of Hazard Trees in Urban Areas, 2nd edition is designed to assist managers or homeowners in evaluating trees for their potential to be hazardous. Hazard ratings cannot strictly define a numerical line for action, between either removal and retention or treatment and no treatment. This must be an administrative decision, one made by the homeowner or manager. In municipal situations, where an agency might manage a very large number of trees, there may be practical limits to the amount of work that can be undertaken, and only the most severe and significant hazards may be addressed. Some level of risk will always be present when people live among trees. The decision of how much risk is tolerable remains with the owner and manager.