Trees vs. Monsoons

Heavy rains and strong winds associated with severe weather pose a significant test for 08-04-05 Tree Work (2)trees that are less than two years old. Frequently, these trees have never before shown signs of weakness or root problems. Although most trees remain unscathed during storms, a small percentage of trees lean or fall during as a result of wind and rain. This is usually a result of un-established or defective root systems.

Immediately following a storm event, DLC maintenance crews visit each damaged tree to determine the best course of action. In the process of evaluating a tree, the base of the tree and its root system is tested for strength and stability. This is done by moving the trunk slightly from side to side to determine if the roots exhibit some degree of establishment with the adjacent soil. Trees that show any degree of root stability are straightened and re-staked. Trees that show no stability, which means they are either broken at the base or root bound (essentially swiveling in the soil), are removed.

Root bound trees can usually be identified by observing the soil when gently shaking the tree. If the ground around the base of the tree moves, chances are the tree is root bound.

Root bound trees can usually be identified by observing the soil when gently shaking the tree. If the ground around the base of the tree moves, chances are the tree is root bound.

Root bound trees may live if re-staked and may continue to show above ground growth. However, experience tells us that these trees will eventually fail since root bound trees never establish good root growth. If root bound trees are re-staked instead of removed, there is significant risk that they will outgrow the stakes and fail again, this time as a larger tree. This can cause significant damage to whatever is in their path.

In locations where trees are removed, replacement trees are selected to include the best quality given the availability and variety. Depending on these factors, some replacement trees will be 15 gallon, 24” or 36” box size. It is important to note that where smaller trees are chosen, they will grow stronger in time because they have more growth time in their new location.

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Poorly established root system allows a storm to knock over this tree

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Girdled roots or a poorly established root system can cause trees to fail at the point of connection

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Roots wound tightly around the trunk are called girdled roots. This will eventually kill the tree

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Nursery containers can cause roots grow in a continuous circle

root-flare

Ideal root growth – roots grow out in every direction almost evenly

Sightlines

What exactly is a sightline obstruction?

Generally, if a tree or shrub near an intersection affects visibility from the ground to approximately 10 feet in height, it is a potential hazard. Maintaining a clear view of approaching vehicles, pedestrians and other obstacles around roadways is important to help limit the chances of an incident due to a sightline obstruction. Common area plants and trees routinely play a role in limiting visibility of signs or at intersections in Communities. There are 2 main ways to address potential sightline obstructions: at design/install and proactive assessments.

During the growing season, intersections should be inspected weekly for common area landscape material that might affect visibility. Creating a program that notes the location of intersections or areas that are frequent offenders is the first step in creating a plan to help the community management and the landscape provider track and react to sightline obstructions. If the issue with a specific piece of landscape material is continuous, consider removing it and replacing it with a smaller plant. Sometimes ground cover plants like lantana and morning glory or small cacti are better choices for areas near intersections. Additionally, consider the same assessment for common area landscape material that encroaches on walkways or into bike lanes. These pedestrian traffic areas should also be reviewed on a regular basis and plant material trimmed and removed as necessary to keep pathways clear for resident use. Most importantly, the main way to address sightline obstructions and risks after the installation of the plant material is with a proactive review and response program.

If you are fortunate to have the opportunity to influence plant installation, pay special attention to plant material near intersections, schools and playgrounds. Also, limit the installation of plants with thorns in areas around walkways to help minimize the instance of pedestrians entering the roadway to avoid undesirable plants. Bougainvillea, ocotillos and other thorny plants should be planned for areas with limited pedestrian interaction. Lastly, pay close attention to the mature size of the plants being planned for new plantings. Almost any plant will work at any location in the 1 and 5 gallon size. Taking a few moments to research the mature size of prospective plants will limit the reactionary response the Association may have to take and limit unneeded expense.

To talk with DLC about sightlines or maintaining your common area landscape, contact Rebecca Herro.

Monsoon Storms

July and August find us squarely in monsoon season. While we welcome the summer rains, the vigorous storms present some challenges for plant material. As your landscape management provider, we are prepared to deal with the effects of monsoon events.

Fallen TreePrior to the monsoon season, DLC Resources, Inc. utilizes a proactive tree management program. Although strong storms and microbursts can damage any tree, we continually seek to minimize tree damage by identifying trees most likely to be severely affected by high winds. These trees are pruned to remove overly thick foliage and dead or structurally unsound branches to minimize the chance the tree will be damaged or cause damage during a storm.

When monsoon storms arrive, the emphasis shifts to clean-up and repair. Typically, the summer storms occur late in the day, after crews have left the property for the day. For immediate emergency aid, we have personnel on call 24 hours a day. These workers are equipped to deal with the most pressing effects of the storm, such as trees blocking streets or sidewalks. Full scale cleanup generally begins the following morning. Normal maintenance activities may need to be suspended or reduced in scope while the crew clean up debris and perform repairs. If necessary, extra personnel will be provided to expedite the storm cleanup.

In spite of the damage these summer storms can cause, there is a silver lining to the monsoon clouds: moisture! The monsoon presents us all with a great opportunity to save water. We assess the amount of water each storm brings and suspend or adjust irrigation schedules appropriately. Not only is rainwater free, it is also superior to irrigation water due to its lower alkalinity. In addition to providing moisture, the rainwater helps leach accumulated salts away from the roots of shrubs, trees and turf.

Assess Your Own Yard

You can benefit from similar pre-monsoon practices in your yard. Assess your trees and have dead branches removed. If the foliage in your tree is exceedingly thick and heavy, have the tree pruned. You may want to hire a Certified Arborist to do the assessment for you.

Following a storm, check the status of your irrigation controller. Power outages can reset irrigation clocks and schedules, and it may not be appropriate for the weather. If your property receives a substantial amount of rain, turn off your irrigation system. Be aware of your plant material and soil moisture in order to determine when the water needs to be turned on again. Overall, you may not need to water as much as you did in the drier months of May and June.

Even if it does not rain, be aware of high humidity; observe the condition of your plants and check the moisture of your soil. The best way to check soil moisture is to stick a screwdriver in the ground. If you are able to insert the screwdriver easily to approximately six inches, there is enough moisture in the soil. If you have difficulty, you may need to apply more water.

Pre-Monsoon Pruning

Proper tree pruning practices are important when attempting to limit storm and wind damage. During monsoon rains, the wet ground makes trees more susceptible to failure due to what we call the “sail effect”. The sail effect happens when trees have been primarily lifted – meaning the tree foliage has been trimmed for clearance. While removing low hanging branches for clearance is an important aspect of tree care, performing it alone leaves the majority of the tree’s weight in the top half – making it more susceptible to wind damage because the wind can’t move through the canopy. The key pruning practice in preparing your trees to for monsoons is crown thinning. Reducing the thickness of the canopy, while also pruning for needed clearance, allows wind to move through the canopy, reducing the amount of force strictly pushing against the canopy.

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DLC follows and recommends the standards adopted by the International Society of Arboriculture (ISA) as outlined in American National Standards Institute (ANSI) A300-2001 Pruning and ANSI Z133.1-2000 when pruning trees:

  • Crown Cleaning (removal of lower branches to provide clearance for view and/or traffic)
  • Crown Thinning (selective removal of branches to reduce weight and increase air and light penetration not to exceed 20% of the total volume of canopy)
  • Crown Reduction (removal of leader or lateral branches using proper heading cuts to reduce size, i.e. reduce leader or lateral to a branch that is at least 1/3 diameter of the branch being removed)
  • Crown Restoration (removal of improperly pruned branches to restore more natural shape)

Even when following the above specification, it is recommended that you not remove more than 20% of the tree’s canopy at a time. Having an ISA Certified Arborist plan your work and and ISA Certified Tree Worker on the ground doing the work helps promote educated and experienced decisions when pruning your trees. Investing in proper tree pruning can save your Community time, money and nuisance when recovering from monsoon damage.

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To experience the value of tree pruning by an ISA Certified Tree Worker, or to have an Arborist assess your tree inventory, contact Rebecca Herro.