Trip, Slip and Fall Hazard: Hidden Depressions in Grade

Successful landscapes require:

  • Proper grading, drainage and amended soil.
  • An automatic irrigation system achieving 100% head to head coverage.
  • Properly installed, high quality plant material.

Each of these functions may require a specific type component, installed at a specific height or location to reduce the potential of creating a site hazard that may result in an accident.  In commercial applications, landscape plans usually include details and specifications dictating type of product and how it should be installed.

Many common landscape products may be improperly installed including:

  • Pop up heads may be incorrectly set to grade against a sidewalk.
  • Valve or drainage boxes set too high or low relative to finish grade.
  • Shrub head installed on a riser adjacent to concrete improvement.
  • Hidden, obscured depressions in grade due to substandard compaction, settlement and subsidence.

    Drainage box set too low.

Improper product selection or substandard installation practices may appear obvious.  A pop up sprinkler head set above the top of  adjacent concrete sidewalk creates a trip hazard.  A drainage structure set well below the turf grade creates a trip slip and fall hazard.  Selecting and installing a spray head on a rigid riser next to a pedestrian sidewalk is a sub-standard industry practice that creates a trip and fall hazard.

Spray head on a riser next to a sidewalk creates a trip hazard.

Not all landscape hazards are visible.  Turf areas may have grade depressions or holes that are hidden by overgrown turf grass.  Depending on the cause and time period, turf grass may completely hide the depth, location and size of the depression or hole, creating a hidden hazard.

A depression, rut or hole may result from several factors.  Repeated mowing on saturated turf may  create ruts.  Overwatering may cause irrigation or utility trench settlement.  A dead tree removed from a turf area may result in a future depression if the grade is not properly backfilled and compacted.

A seven inch deep hole hidden by turf grass.

Bermuda grass is a fast horizontal spreading turf-grass used in parks and recreation facilities throughout the country.  Unless regularly aerated and de-thatched, Bermuda grass in known to grow a  thick layer of thatch.  Over time, the thatch layer can increase the turf grade several inches above adjacent sidewalk and curbs.

The backfill in utility trenches installed across pre-existing turf may settle, creating a depression in the sub-grade.  The photo depicts the edge of a trench cut across an asphalt driveway, across a turf area.  The trench backfill eventually settled, creating a trench sub-grade depression hidden by the Bermuda grass.

Thatch, hidden depression and sanded turf.

The depression resulted in a trip and fall accident.  After the accident, several hidden turf depressions were “sanded” to fill  depressions to proper grade.

Not all landscape hazards are open and obvious.  Even a perfectly installed landscape may develop hazardous conditions if not regularly inspected and maintained.

Irrigation systems should be monitored, inspected, tested and adjusted monthly.  Turf should be trimmed around utility boxes and vaults regularly, aerated and de-thatched annually to maintain optimum performance and minimize grade changes.  Drainage structures should be grade adjusted, repaired or replaced when damaged.  Valve, electrical and junction boxes should be monitored for grade changes and adjusted as required.  Bark mulch thickness should be monitored and supplemented annually to maintain proper coverage and grade.

In summary, a properly installed landscape is composed of several systems and components that require regular ongoing maintenance for optimum performance, efficiency and safety.  Pro-active landscape maintenance may reduce potential hazards, resultant accidents and lawsuits.  These actions demonstrates an Owner’s recognition of protecting the health and safety of the public, pedestrians, friends and family who may visit and use the site and may prove useful in a legal action.

A Horticulturists Local Neighborhood Walk

I took my usual walk through local neighborhoods surrounding Balboa Park in San Diego.  A glorious spring day, I couldn’t help but marvel at the beautiful ornamental landscape trees, shrubs and vines in bloom everywhere!  Very uplifting, glad plants are not affected by the virus!

Arborist Online Learning Opportunities in the Covid Era

In a recent blog, I discussed using online media for a site online site inspection involving a Torrey pine tree root conflict with adjacent asphalt paving.  That marked the first time I used an online media tool rather than being physically present at the site.  My client and I used Facetime to conduct the real time inspection.

As the restrictions ease, I believe the use of online media such as Zoom, Hangouts, Facetime etc will increase.  I have already presented this concept to a legal client in Northern California concerning an irrigation inspection.  Do I really need to fly from San Diego to San Francisco, rent a car, drive to the site, observe irrigation defects, then reverse the process returning home or, can I watch the inspection over the web?  The level of scrutiny required depends on the individual case.

A slide from Dr. Smiley’s presentation

Like so many other industries, the tree industry is rapidly adapting to the new Covid – 19 reality.  Today, I attended an online Zoom seminar titled Sidewalks, Urban Plazas and Tree Roots.  This seminar was presented through the ISA Southern Extension.  I believe it was originally going to be part of a “normal” ISA Southern Association Annual meeting that was cancelled due to Covid.

The online presentation occurred through Zoom with over 1000 arborists throughout the U.S. and other countries attending. The topic concerned tree roots damaging sidewalks, presented by Dr. Thomas Smiley.  Once a few technical glitches were adjusted, the presentation was almost identical to what I had experienced attending many seminars.

The slides presented alongside the audio streaming from Dr. Smiley was easy to view.  I became immersed in the content and found myself taking pics of some of the slides.  The topic provided test data results using different techniques designed to reduce root intrusion beneath sidewalks.

Incorporating root growth inhibitor practices

 

The presentation lasted an hour, same amount of time I’m accustomed to when attending a seminar.  Although I already knew a great deal about the topic, I still came away with new information for use in my practice, including a great specification detail incorporating multiple root growth inhibitor practices that may reduce sidewalk damage due to roots.

In the past month, I’ve been able to continue my consulting practice from my home office.  I’ll continue to utilize more online media tools, whether for learning, conducting site inspection work, and client meetings.  I believe these new opportunities are one of the (few) beneficial results from the Covid-19 virus.

I recently provided a client with a proposal to develop landscape maintenance specifications for commercial properties located in several different climatic regions.  The proposal did not include any site visits.  All data collection would occur online through various means.  Using online data collection versus conducting multiple site visits saved the client thousands of dollars.

I’m looking forward to these new opportunities utilizing online media sources as potential replacement for physical presence.  Hopefully it will prove an efficient, effective, cost saving technique without sacrificing product accuracy.

 

 

 

Old Growth Redwood Destruction Continues

I read an L.A. Times article discussing ongoing logging of redwoods in Humboldt County.  In a battle spanning several generations, tree sitters and eco-activists are putting their bodies on limbs in redwood tree tops to prevent logging.

This is not the first time tree activists have climbed hundreds of feet up old growth redwoods to prevent logging the tree and surrounding trees.  It reminded me of a remarkable novel I read called “The Overstory” by Richard Powers.  The novel is about people and their interaction with and the affect specific trees and forests.

It primarily focuses on loss of old growth redwoods and firs in the pacific northwest and activists actions to prevent tree and habitat loss.  However, the novel was historical, taking place several decades ago.  Yet it appears old growth logging in Humboldt county continues to in present.

I recently visited, camped and explored the Jedediah Smith State and National Redwood park, not far from where present day logging takes place.  For me, the thought of logging off trees that are hundreds to over a thousand year old is difficult to accept.

We have commercial redwood farms for harvesting lumber.  Of course, it does not possess the grain, size, color and characteristics of true old growth redwood trees.  If we want future generations to be able to view and experience the incredible creation of a true, old growth tree, we MUST stop logging and preserve this resource.

Joshua Tree Extinction by End of Century?

I just read an article in the Los Angeles Times about a potential listing of the Joshua tree as an endangered species.  The western Joshua tree, Yucca brevifolia, is one of two genetically distinct species that occur in California.  It range extends from Joshua Tree national park westward along the northern slope of the San Bernardino and San Gabriel mountains, northward along the eastern flank of the Sierra Nevada and eastward to Death Valley.

Approximately 40% of the western tree range is on private land, the eastern range is centered in the Mojave National Preserve and eastward into Nevada.

After decades of climate change, development, drought and wildfires, the species is facing a rapidly increased the risk of extinction.  State Department of Fish and Wildlife Commission will decide in June whether to accept the department’s recommendation to declare the tree an endangered.

As usual, there are two sides to the issue.  Conservationists see this as a triumph of state environmental law while critics claim it as a misguided overreach because Joshua trees are already protected under many city and county ordinances and within the 800,000 acre national park.

Environmentalists argue existing state and local ordinances are largely inadequate at protecting species habitat loss, the endangered species listing will finally provide a statewide protection for the species, including requiring wildlife managers devise a recovery plant for the species, which could limit development in SoCal real estate.

The Joshua tree exists in high desert communities such as Yucca Valley or Hesperia, communities with lower average median household incomes.  They are concerned the listing would impose additional burdens to real estate development, making it tougher to improve their property or curtail new development in their communities.

However, researchers warn time is running out.  The tree’s range is contracting at lower elevations, its reproduction has come to a halt.  Trees are failing to reproduce at lower, hotter elevations.  They could become extinct in California by the end of the century!

This would be a terrible outcome for a truly incredible species.  This remarkable species deserves protection.  I believe this tree, in its own way is as majestic in its high desert setting as the coast redwood.  These are species distinct to our California heritage.  The Joshua tree deserves protection for our future generations to enjoy, marvel and be uplifted by this unique species.

Download a pdf of the article here:  Los Angeles Times – eNewspaper

California Olive Trees Dying from Exotic Pest Infestation

Olive tree displaying decline symptoms

With so many trees dying in natural and landscape settings, I’ve observed a disturbing trend throughout San Diego, and I assume most of the state.  Property owners allowing dead and declining trees, palms and shrubs to remain in place.  The problem with this practice, aside from aesthetics, is the dead plant may serve as a vector, whereby flying insects such as beetles, leaf hoppers, spittle bugs etc. may spread the disease to other uninfected trees.

Over the past decade, drought and climate change has taken a toll on millions of trees throughout California.  Drought weakened trees succumb to secondary invaders such as wood boring bark beetles.  There appears to be a continuous proliferation of new exotic pests resulting in diseases that are killing millions of trees in nature and within our urban forests and residential landscape settings.

Gold spotted oak borer

First collected and identified in 2004 was the gold spotted oak borer, (GSOB). This flathead borer is responsible for killing over 100,000 live and black oaks in San Diego County alone.  There is no effective prevention or cure.

Reports of the disease known as citrus greening, previously confined to China, appeared in Florida, threatening the entire U.S. industry.  The disease is a vector-transmitted pathogen by the

Citrus damaged by Asian citrus psyllid

Asian citrus psyllid.  This disease ravaged Florida citrus growers.  Once infected, there is no cure.

Another exotic pest first detected in Southern California in 2003 has been infesting hundreds of different species and is now established throughout the southland.

The Polyphagous shot hole borer is a small ambrosia beetle responsible for transmitting Fusarium disease to many tree species including avocado,

Sycamore bleeding from shot hole borer

box elder, coast live oak, maple, liquidambar, coral, sycamore and many other species. Fusarium is a vascular clogging disease for which there is no cure.

The list goes on and on.  Climate change and an ever more connected world will continue the trend toward future invasive erotic pests.

In early 2000, olive trees, (Olea europea) became very popular as a landscape tree, heavily planted throughout southland landscapes. For the past decade, olive trees have been declining from a number of diseases.  Two of the diseases are fatal, both display similar symptoms, making diagnosis difficult.

Foliage display tip and marginal burn symptoms

Symptoms appears as leaf marginal burning, tip dieback, leaf scorch, and loss of foliage color.  Defoliation proceeds from the top down and outside in toward the trunk.  Small twigs die back, eventually larger branches and entire limbs die. Depending on location and season, the decline may be rapid or slowly over the years.

 

Xylella or Verticillium?

 

Disease Infection

  1. Diseases known as quick decline, leaf scorch, or variegated chlorosis are caused by Xylella fastidiosa, the bacteria best known for causing Pierce’s disease on grapes, but also attacks citrus, peach, almonds, oleander, olives and many other species.
  2. Verticillium wilt affects olive trees in commercial and landscape plantings and many other species. The disease is caused by soil-borne fungi, Verticillium albo-atrim and dahliae.

Both are vascular clogging diseases, where the fungus or bacteria spreads throughout the vascular system, restricting water movement within the xylem tissue.  However, they have separate means of transmission. Unfortunately, neither disease has a cure, infected trees and shrubs decline over time, usually resulting in death.

Description and Spread

  • Xylella is transmitted by the glassy-winged sharpshooter, (Homalodisca vitripennis), leaf hoppers and spittle bugs. These vectors are xylem feeding insects.
  • The pathogen multiplies and spreads throughout the host tissue, restricting water movement through the xylem tissue.
  • Insect vectors feeding on infected trees (such as olive and oleander) may acquire the bacterium and carry it to new hosts.

 

Verticillium is a soil-borne fungus, it invades the root system of olives when the soil temperature is cool.

  • After penetrating through roots, the fungus multiplies within the xylem tissue, interrupting and reducing water movement from the roots to the leaves.
  •  Each disease clogs the vascular system, interrupting water movement from the roots to the leaves.
  •  Both diseases have similar symptoms making identification difficult.

Common Symptoms:  (not all symptoms may be present) 


Xylella:

  • Tip burn

    Leaf scorch beginning at the tip toward the stem (petiole).

  • Marginal browning, scorch and yellowing.
  • Twigs and branches dieback beginning in the upper crown.
  • Desiccated leaf and fruit drop.
  • Production of suckers.

    Crown dieback

 

Oleander infected with Xylella

 

 

 

 

Verticillium:

  • Symptoms appear in spring.
  • Newer leaves curl inward.
  • Dead fruit clusters remain attached.
  • Loss of leaf color and luster.
  • Leaf and fruit drop follow.

    Inward leaf curl

Progressive decline

 

 

 

 

Dead fruit retained

 

  • Individual branches and or large portions of the tree may die within one season.
  • The tree may not die, growth may develop on unaffected portions of the tree and suckering from the crown.
  • The new growth continues until re-infected; the cycle repeats the following year.

    Vascular staining

  • Vascular staining may be present.

Control

There is no cure for Xylella or Verticillium.  Recommendations for both diseases include:

  • Remove suspected plants immediately to prevent vectoring disease to other susceptible host plants, i.e.: olive, oleander, sweetgum, grapes, etc.
  • Integrated pest management to control insect vectors may help slow disease spread but spraying to control leafhoppers is expensive and futile.
  • Control of nearby weeds and grasses to help limit insect vectors.
  • Pruning out infected limbs may improve the appearance, but it is impossible to prune “below” the infected wood, so pruning does not get rid of the disease.
  • Fungicide applications are not effective.
  • Remove declining and dead trees immediately.
  • Replant with disease resistant species.

Avoiding the disease is most effective but not always possible.   Soils are easily contaminated with Verticillium from former planting and the pathogen may survive in the soil for several years, ready to infect newly planted susceptible species.

While greenhouse soils may be heat pasteurized to kill the fungus, that is impossible in the landscape.  Solarizing landscape soils has some effect at reducing verticillium infected soils.  Prior to planting, rototill and irrigate the soil as deeply as possible.  Cover the area with six mil plastic, seal the edges with soils to secure for six to eight weeks.

Effective cultural practices such as fertilizer application, irrigation management, weed and insect control may assist in preventing infection and possibly reduce the effects of the disease.  Most of these practices focus on improving plant vigor that help mask the disease, however these treatments are not curative.

It is important to note, many of the foliar symptoms described above may also be due to drought or poor irrigation practices.  There are also foliar diseases that may produce similar symptoms but are only minor and may not pose a serious threat.

Diagnostic laboratory testing is the definitive method for a positive identification of the disease. 

The important take away is this:  Don’t ignore decline symptoms in olive and other susceptible species, as the plant may be infected with a fatal vascular disease.  Declining and dead trees left in place may serve as a source for the disease to be vectored by beetles, sharpshooters and other pests to healthy nearby trees.  Remove dead or dying trees to prevent disease spread.

RDCS LLC Hired as Consulting Arborist by PCL Construction for UCSD Triton Pavilion Project

PCL Construction, is the general contractor managing the Triton Pavilion project at UC San Diego.  PCL Triton Pavilion.  The Triton Pavilion project includes developing a new, large student center and be a future major stop for the San Diego trolley Blue Line.  The trolley Blue line expansion to be completed in 2021 will connect downtown San Diego to University City. Union Tribune Article

To determine how to manage existing campus trees in conflict with future construction, PCL hired Rappoport Development Consulting Services LLC as a sub-consultant providing arboricultural consulting services.  Mr. Jeremy Rappoport, President of RDCS, will assess and tag all the project trees and develop a tree inventory.  The inventory will identify the tree, trunk diameter, crown height,  quantity, structure and health condition.  These metrics will assist in determining tree retention, protection, and relocation.

RDCS founder Jeremy Rappoport is an ISA certified arborist, tree risk assessor qualified, ASCA Registered Consulting Arborist (RCS #564), C-27 California Landscape Contractor #436000 and a professional horticulturist.  RDCS LLC provides arboriculture, landscape, horticulture and land development consulting services for civil engineers, landscape architects, prime contractors, municipalities, HOA’s, commercial and residential property owners and  expert witness litigation and support services for plaintiff and defendant attorneys and insurers.

Tree, Plant and Landscape Appraisals for Damages Caused by California Wildfires

The Woolsey Fire

Once again, Californian’s throughout the state continue to suffer devastating losses due to wildfires.  From the southland to northern California and the foothills of the sierra’s, the Woolsey, Camp, Hill and seemingly countless other fires have ravaged our state.  From October through December, Santa Ana winds fan destructive blazes that grow in size with each passing year.

During recovery efforts, insurers and attorneys require a tree or landscape appraisal to settle a client claim.  In the past year, RDCS  provided appraisals for damages caused by  the Thomas fire in Ventura and Santa Barbara counties, the Lilac fire in San Diego North county, the Liberty fire in Riverside County, Pocket fire in Geyserville, and the Erskine fire in Lake Isabella.

I recently published an article on the importance of specialized tree and plant appraisers  for determining the cost and value of fire damaged trees, plants and landscape.  Read the article  Fire Damage & Tree Appraisal.

The Walk to End Alzheimer Disease Was a Tremendous Success

To was the San Diego Walk to End Alzheimer Disease and it was a moving event.  Thousands showed up to support this worthy cause.  The walk exceeded the goal of raising over $150,000.  Through so many donations, WE managed to raise almost $600, and we were rewarded with a medallion for achieving “Champion Club” status.

It seemed everyone their had a friend of family member affected in some way.  The feeling of community and support was very emotional for me.  I thought about my mom a lot today, at the end of the walk, I felt really good contributing to the effort.  There were great speakers, including the Mayor, and I met and spoke with wonderful people.  A shout out to Delores, great talking to you today, good luck on starting your new job Monday!

Well, I have posted pictures of the event, thanks again!

  1. Sincerely, Jeremy20170909_091001
    Pre-walk selfie, feeling good!

    Pre-walk selfie, feeling good!

    A little love before the walk

    A little love before the walk

    Love the flowers

    Love the flowers

The Walk to End Alzheimer Disease

While I have a rule to not use the company blog to post personal information, I decided to bend the rule for a cause very near and dear to my heart.

My mother, Audrey Rappoport, suffers from Alzheimers. This debilitating disease affects millions of people and their families. I am participating in the Walk to End Alzheimer Disease in San Diego to honor my mother and help to find a cure.

Please consider a donation http://act.alz.org/site/TR?px=13644019&fr_id=10407&pg=personal to a very worthy cause that will help us all find a cure to this horrible disease. Thanks for your support

Sincerely,

Jeremy Rappoport