Tag root compaction

Damage from construction projects is the most common cause of tree death in urban environments, and while the effects may not be immediately apparent, the tree can be in decline and die years after nearby construction has been completed.

Injury to a tree happens unintentionally from mechanical tree injury, root damage, loss of rooting space, changes in soil moisture, soil compaction and contamination.

Why? Lack of construction protection and lack of understanding what constitutes the critical root zone of a tree.

The most common problems associated with construction:

• Root loss is generally caused by stripped soil, sub-grade preparation for pavement and trenching for utilities. Severing one major root can cause the loss of 15 to 20% of a root system.
• Mechanical wounds (to limbs or trunks) caused by machines, poor pruning, high-traffic, and people.
• When the soil grade is lowered a large percentage of roots may be removed. When the grade is increased a tree can be smothered because 90% of absorbing roots are in the top few inches of soil.
• Soil compaction smothers trees by reducing available oxygen and decreasing a tree’s ability to absorb nutrients and water. This causes the roots to be more exposed to the elements, as they struggle to absorb water and nutrients.
• Spills or dumping of fluids (paint, oil, fuel, etc.) can cause quick and rapid death of a tree.

During the planning process

Decide which trees will be kept, which trees must be removed and which trees need to be protected. Consider tree location, tree size, tree heath, tree species, species diversity and tree age (younger trees usually withstand construction better than more mature trees). Then assess the potential impact to the trees and make modifications in plans when possible. Identify tree work that must be done (pruning and crown-raising where necessary, treatments, irrigation, fertilization, mulching, and pest management) under the supervision of a Certified Arborist.

Before beginning construction

• Tree Work
  This should be performed under a certified arborist’s supervision and should include the necessary pruning, removal of dead wood, and removal of trees. This is ideally done in the winter time while the trees are dormant and at least 8 months to a year before construction begins. This is the time to begin a deep root fertilization and Tree Health Care Program that will help strengthen and protect your tree.
• Erect Barriers
  The barriers should be as far from the base of the trunk as possible or a minimum of the drip line. Within the Tree Protection Zone, mulch should be applied 2-4 inches deep around the base of the tree within the barrier.
• Mulching
  Where barriers are not possible, avoid compaction by mulching 6 inches deep and laying plywood on top to disperse weight. For removal of mulch at the end of the project consult with an arborist.
• Reduce Chance of Harm
  Limit access to site to avoid unnecessary soil compaction: Create one road in and one road out of site with barriers on either side. This route can later be used to trench for utilities, water lines, driveway, etc.

During construction

• Water
  Water trees frequently with slow soak. If roots have been damaged or removed, then a tree will need more water than it did before because it has less ability to uptake necessary water.
• Feed
  Trees should be fertilized at least three times a year. We suggest a deep root organic fertilizer to increase available nutrients.
• Pest And Disease Control
  When trees become stressed from construction they are more vulnerable to pest infestations and other diseases.
• Pruning
  During construction, we only want to remove what is necessary for the project to continue. This includes damaged limb, dead wood, or infected sections. No other pruning should be done if not necessary.

Post construction

To help enable survival of your trees, treat and seal crown and trunk injuries, cable and brace, repair irrigation and drainage issues harmful to trees; remove excess mulch and mulch for long-term health of tree, aerate soil that has been compacted, fertilize for the next few years. Have the trees inspected seasonally by a Certified Arborist.

Symptoms of tree stress from construction damage

Short annual shoot elongation, small yellow leaves, thin foliage, leaf wilting, early fall coloration or defoliation, epicormic shoots, twig dieback, branch dieback, irregular wounds, secondary pest problems, and decay at wound sites.

At Texas Tree Surgeons, we love trees and we love our community! Trees are a wise investment of funds because landscaped homes are more valuable than non-landscaped homes. If you are planning to remodel, or do construction we would love to help safeguard your trees. Contact us today!

One hallmark of summer is the dense, green foliage on broadleaf trees, but less-than-ideal circumstances can cause the rich green of healthy leaves to become pale, yellowish, and translucent. This loss of color is caused by a deficiency in chlorophyll, which is an essential part of a tree’s nutrient-gathering process. While yellowing leaves can be a sign of several different conditions, in North Texas, yellow leaves on a tree that is usually green are most often a sign of iron deficiency (“iron chlorosis”). Since the historic freeze in February 2021, we have seen a higher number of trees exhibiting iron chlorosis, as they are still recovering from freeze damage and related stress, and their ability to get essential nutrients has been compromised. Luckily, most cases of chlorosis can be remedied by soil amendments and correct, targeted fertilization.

Why Are My Tree’s Leaves Yellow?

While it is expected to see pale green or yellowish new leaves on a tree during spring, the color of these young leaves should darken as they mature. By summer, most healthy deciduous trees should exhibit rich, green leaves. (There are some species of tree with naturally red, purple, or other-colored leaves, but these are less common in North Texas.) If a tree never “greens out,” or turns green but starts to fade well before autumn, there is a systemic health issue at play. Dead or dying leaves can turn yellow, but quickly become dark grey or brown. If a tree’s leaves become pale green or yellow, and stay that way, something is preventing the tree from generating enough chlorophyll.

Chlorophyll is a naturally-occurring chemical in most plants, and performs an important function in leaves. Chlorophyll is responsible for absorbing sunlight and converting it into usable energy for the plant. Chlorophyll is adapted to absorb as much of the correct type of light as possible, and that chemical makeup causes its green appearance. While other chemicals in the leaves can appear as other colors, in most plants, chlorophyll is present in a higher concentration than other pigments, and so it is the one we most clearly see. For a majority of plants and trees, vivid green leaves are a sign of good health and proper nutrition. When leaves begin to decline and die, as in the fall, the chlorophyll fades and other colors can be seen, which is why we see a leaf color change. Similarly, health issues and stress can make plants’ leaves change colors, as the necessary chemicals become imbalanced.

What Can I Do About Chlorosis (Leaf Yellowing)?

While the underlying cause of leaf yellowing (chlorosis) is chlorophyll deficiency, that deficiency may be caused by a number of factors:

• Mineral/nutrient deficiency
• Soil acidity/alkalinity
• Poor drainage/overwatering
• Root damage/compaction
• Herbicide exposure
• Bacterial/fungal infection

Management of the cause of chlorosis is the key to bringing a tree back to health. While some factors, such as soil pH or previous chemical exposure, may not be easily remedied, drainage issues and nutrient deficiencies can often be successfully resolved. Identification of the exact cause of chlorosis can be tricky, and there may be more than one contributing factor. For a comprehensive assessment, contact an ISA Certified Arborist who can examine not only the tree itself, but the surrounding environment, and can ask the right questions to properly understand the tree’s history. Local certified arborists also have access to plant pathologists and other experts, and may be aware of a widespread issue that is affecting your tree.

A NOTE ABOUT WATERING AND FERTILIZATION

A common knee-jerk reaction to a tree or plant not doing well is to immediately increase watering and start applying fertilizer. If the chlorosis is caused by excess soil moisture, however, more watering can cause even quicker tree decline. Similarly, applying a standard, high-nitrogen fertilizer may bring temporary improvement, but can cause further chemical imbalance in a nutrient-deficient tree and stimulate quick growth that is unsustainable. It is important to understand and address the specific cause of leaf yellowing before taking action. Contact an ISA Certified Arborist for assessment and recommendations, and consider sending a sample to a plant diagnosis lab for the most accurate information.

At Texas Tree Surgeons, we love trees and we love our community! We are seeing post-freeze chlorosis on many trees in North Texas, and are working with the International Society of Arboriculture Texas Chapter as well as experts at Texas A&M University and in the tree care profession to provide the best care for freeze-stressed trees. If you have questions about your trees, freeze-related or not, don’t hesitate to get in touch!