At Yosemite, Infrastructure Out to Benefit Giant Sequoia’s!

Read an article in the Los Angeles Times concerning upcoming changes at Yosemite National Park. There is a proposal to remove public parking, a gift shop and tram operations in an effort to minimize impacts to the Mariposa Grove, a grove of approximately 500 Giant Sequoia trees (Sequoia giganteum).

The Park service recognizes paved surfaces and infrastructure are “compacting the soil, encroaching on sequoia roots and interfering with natural drainage patterns”. Tram service will be limited to the south entry of the park and shuttle buses would take people tot he entrance of the lower grove, where the largest and oldest trees are located. Access to the upper grove would be by foot only. Approximately four acres of paved surfaces would be removed from the grove. A final decision on the proposal will be made by end of the year.

Measured by mass, the giant sequoia is the worlds largest living organism. Californian’s are fortunate to have bragging rights to hosting these ageless giants living on the western slope of the Sierra Nevada. They exist in scattered groves typically on federal land.

My dad took me to Sequoia National Park when I was just a young kid, I still vividly remember the awe I felt looking at the General Sherman tree. If you haven’t seen a giant sequoia, you owe yourself and family a trip to Yosemite or Sequoia National Park to see these living legends. Their sheer mass and regal beauty is indescribable. I think this is great news for the future survival of the sequoia grove, which we almost lost due to the recent mammoth fire at Yosemite.

When trees conflicts with infrastructure, tree usually loose out.  It is an encouraging turn of events when trees are recognized more valuable than a parking lot and gift store, hopefully this trend will continue.

Read the article at Redwood Grove Saved

Can a Tree Capture Particulate Matter from the Air?

For years, certified arborists and urban foresters have learned the many benefits of trees. Energy savings are one of the foremost known benefits of trees as they shade building during the summer reducing the need for air conditioning and deciduous tress allow sunlight to reach structures during winter months, solar radiation decreasing the need for winter heating.

Another known benefit for trees are their ability to reduce storm water runoff and erosion, particularly during the winter months. Tree root systems bind soil particles and slow storm runoff from roofs and other impervious surfaces, trees act as bio filters, slowing storm and irrigation water runoff and allowing the water time to slowly percolate into the soil profile rather than run off into the street or storm drain system.  By forcing water to pass through the soil profile, rather than runoff into storm drain systems, the soil mass filters impurities before the water enters into streams, ponds and aquifers.

Birch Tree planting works as filter

A Birch street tree planting used for testing as a green filter to remove particulate matter from the air we breath

Continue reading “Can a Tree Capture Particulate Matter from the Air?” »

Trees and Solar Power – Environmental Conflict or Can the Two Co-Exist?

I attended a recent seminar in San Diego entitled Trees and Solar Power:  Natural Partners, sponsored by the California Urban Forest Council (CAUFC).  It was a very informative seminar, bringing together professionals from the solar and tree industries, as well as city planners, landscape architects, arborists and related professionals.

Even with decades experience as a landscape contractor, certified arborist, professional horticulturist and land development infrastructure project manager, I was not aware of the current solar and arboriculture laws.  For example, the State of California and many other states enacted solar legislation decades ago.  Due to the oil crisis in the 1970’s and 1980’s, there was increased interest in promoting alternative energy sources.  Many states adopted laws to encourage renewable energy technologies, solar being one of them.

In 1978, California enacted the Solar Shade Control Act, in part to protect consumer rights to install and operate solar energy systems on a home or business and to protect consumer rights to access sunlight.  In 2008, the law was amended due to a very public controversy between two Santa Clara County residents being criminally prosecuted and convicted under the Act for allowing their redwood trees to cast shade on a neighbors solar panels.

Based on the Solar Shade Act of 2008, a site plan reflecting the pre-existing conditions at the time a solar system is installed should be a mandatory permit and legal requirement.  As lawsuits increase due to conflicts between trees shading solar collectors, a site plan showing trees in place pre-existing a solar installation will become an important legal instrument.

We derive many benefits from large trees, from their beauty and aesthetics to the shade and passive cooling affect they have on our homes and businesses.  The same is true for deciduous trees in the winter when they drop their leaves, permitting solar radiation to warm our homes.  In a residential setting, large existing trees will invariably cast shading onto a structure.  It is incumbent upon a solar company to analyze shading from the Client and neighboring trees for correct solar panel design and installation.

If a solar company identifies trees as a potential shading  conflict with a rooftop solar installation, a certified arborist and or professional horticulturist should be added to the design team.  Depending on the tree species, growth form, and distance from the structure, there may be several alternatives available to mitigate tree shading without complete tree removal or butchering the tree through indiscriminate topping.

Have a certified arborist or professional horticulturist consult with the solar company to ensure retention of the desired landscape aesthetics combined with the energy savings benefits of rooftop solar.

Read the full article at Trees and Solar-Environmental Conflict or Can the Two Co-Exist?

Love the Beauty of Your City? Thank the Landscape Architects who Made it Happen

I recently read a great article by Delle Willett of the North Park News entitled Landscape Architects:  Artists with the Earth as a Canvas.  The article focused on three local women landscape architects who have made significant contributions to enhancing the aesthetics and functionality to the City of San Diego.

While reading about the history of female landscape architects, I couldn’t help be reflect on my own background and education within the fielof landscape architecture and landscape contracting.  As a college student, my path began at UC Santa Barbara and completed with a Bachelor of Science degree from California Polytechnic University, Pomona.

I wrote and article correlating my own academic history with the three landscape architects discussed in the newspaper article.  For men or women interested in the field of landscape architecture, design, planning, horticulture, arboriculture and landscape contracting, or anyone who struggled to find their own passion and career path in college, I think you’ll enjoy the read.

Landscape Architects Making Significant Contributions to City of San Diego

Landscape Architects: Artists with the Earth as a Canvas.

 

 

PTCA Field Day a Great Success

Wow, just when I thought the PTCA (Professional Tree Care Association) annual seminar was the bomb, the following field day was just as great. While the seminar was an indoor event focusing on a variety of topics presented by outstanding industry professionals and educators, the field day was spent outdoor at beautiful Balboa park in San Diego.

The day consisted of a number of workshops organized into several different tracks that allowed participants to choose from a palette of presentations that provided something for everybody. Tree climbers and field workers loved the tree climbing workshop and training by Mr. Martin Morales. His workshop included climbing and positioning for safe work in trees, also taught about knots, ropes and equipment inspection, while providing new tips and tricks. I am way to old for climbing, but enjoyed watching guys in the trees, had an opportunity to meet Martin during an incredible lunch (carne asada). We were looking at a rigging holding a tree logIMG_0042, he immediately pointed out flaws and worn equipment, I would never have noticed. Fortunately we have educated tree climbers who understand the importance of proper equipment, training and safety.  Another track included Tree Risk Assessment best management practices (BMP’s) workshop taught by Mr. Ron Matranga and Dr. R. Bruce Allison. Since I consult and provide tree risk assessment as part of my practice, it was a great opportunity to learn about  best management practices involved with the new TRAQ (tree risk assessment qualified) versus the previous TRACE (tree risk assessment certification exam) methodology. Dr. Allison demonstrated new sonic tomography techniques for non-destructive testing of the interior of tree trunks, new cutting edge technology that is already an advancement from just two years ago. Using probes and determining the time for sound waves to travel through tree trunks and how the sound wave moves at different velocities around interior trunk decay will assist arborists to use in advanced tree risk assessment. As Dr. Allison noted, hopefully in the next few years, the cost will come down and we will have a pocket sized device and an app to use to help us understand what is happening with interior tree decay.

Sound wave technology, the next big thing?

Sound wave technology, the next big thing?

How serious is the problem

How serious is the problem

We all know about new invasive insects and diseases affecting our trees, new invasive species are being detected at a rate on one every 60 days, Dr. John Kabashiima provided the sobering statistic it is now one every 45 days! The gold spotted oak borer has decimated tens of thousands of Coast Live Oak and Black Oaks throughout California.

Six orange color dots help identify this pest, although the adult is rarely seen

Six orange color dots help identify this pest, although the adult is rarely seen

This pest has been spread throughout the state, particularly San Diego county by people using the dead wood for fire wood, transporting it in their vehicles where they unwitting spread the insect throughout the county. Don’t move infected wood!

Stop using infected wood for fire wood and don't transport the wood, you are spreading the disease

Stop using infected wood for fire wood and don’t transport the wood, you are spreading the disease

Take a look at some of these nasty borers and other insects, yikes!Nasty Borers

For pest control advisors and applicators, there was a pesticide application for trees demonstration and a safety workshop and tree identification workshop and quiz available to test your knowledge. Field guys loved the chainsaw sharpening and troubleshooting workshop presented by Mr. Paul Lasiter and Mr. Joe Garcia. Another great aspect for everyone was presentation of many workshops in Spanish and English, a very inclusive aspect that helped all of us enjoy the day.

I learned a great deal of new information I never would have even considered without this great field day presentation. Have you ever considered how heavy a downed tree trunk is?  Well, there was a workshop on how to calculate the wood weight of felled trees, presented by Mr. Harvey Pedersen. Crane operators have to have a reasonable idea of how much a log or portion of a tree trunk weighs in order to safely lift it. Mr. Pederson presented wood weight calculations of various types of trees and an amazingly accurate method for estimating the weight of a log, which was then lifted by the crane which provided the true weight to compare against our estimated weights. How cool is that!

How much do those logs weight?

How much do those logs weight?

Just want to thank all of those involved in the PTCA Seminar and Field Day for a truly memorable event, a special thanks to our friend Dave Shaw

Dave kept us all entertained, what a great guy!

Dave kept us all entertained, what a great guy!

 

who once again served as the master of ceremony and kept us all entertained. Keep up the great work, looking forward to next years seminar and field day.

Learn more about the PTCA at http://www.ptcasandiego.org

PTCA Arbor Essence

No, this is not a perfume, rather it is the title for this years PTCA Seminar and Field Day.  PTCA, known as the Professional Tree Care Association of San Diego, is a premier industry association for professionals within the tree care industry.  The association contains a wide diversity of professionals, including representatives from outstanding tree care and tree service companies, ISA (International Society of Arboriculture) certified arborists, utility arborists, board certified master arborist, ASCA (American Association of Consulting Arborists) RSA’s (Registered Consulting Arborist), and industry professionals from utility companies, San Diego Zoo, golf courses, private industries, landscape contractors, landscape architects, educators and more.

A common thread shared by all of these different professionals and educators is our love of TREES and desire to further improve our understanding of the field of arboriculture!  It is a comforting feeling sitting is a room with hundreds of people sharing our knowledge and experiences with trees, learning new information, meeting old and making new friends.

Each year, the PTCA sponsors the annual Seminar and Field Day.  The first day (today) featured an incredible diversity of speakers and topics, there is something for everyone.  Here is a sampling of todays speakers:

Ms. Leah Rottke, professor at Cuyamaca College spoke about what to plant now for upcoming changes brought about by climate change in Southern California, Ms. Pat Nolan, County Pathologist for San Diego County of Department of Agriculture spoke about invasive diseases  moving into the Urban Forest.  In the morning session, Dr. Tom Scott, Ph.D., Department of Earth Sciences, UC Riverside discussed Management of Oak trees in San Diego County followed by an afternoon discussion about the Gold Spotted Oak Borer research (GSOB) and update.  Mr. Ron Matranga, Board Certified Master Arborist from Atlas Tree Service provided an overview of the ISA Traq (Tree Risk Assessment Qualified) program and Mr.Randall Stamen, Esq., from Riverside, California delivered a sobering lecture about Arboriculture and the law, including tree risk assessment and case studies.  Mr. Brian Bishop of Bishops Tree Service discussed improving the efficiency of tree crews and Dr. John Kabashima, Ph.D., UC County Extension, Orange County gave an entertaining lecture about effective sampling for diagnoses of insect and disease problems.  All of that in ONE day!

Really looking forward to tomorrow, the field day featuring workshops in tree risk assessment and BMP (best management practices), insects and diseases of shade tree diagnoses, pesticide applications for tree demonstrations, safety and tree identification, electrical safety, wood weight calculations, improving efficiency and maximizing safety.  There will be a tree climbing workshop provided in Spanish and English.

If you are a tree, landscape, horticulture, educator, consultant, or expert witness and have not yet attended a PTCA field day, you are missing out on a premier educational and entertaining event.  Members of the ISA, ASCA and urban forest councils, city and jurisdictional representatives, recreational and utility companies all come together in a common bond of learning, teaching and sharing, not to mention fantastic networking opportunities.  Hope to see you at the next PTCA Seminar and Field Day!

Learn more about the PTCA at http://www.ptcasandiego.org

Is Global Warming Affecting Redwood Trees in California?

I read a very interesting article in the L.A. Times concerning possible affects of global warming on both the Giant and Coastal Redwood tree populations in California. There might actually be some good news associated with global warming, recent scientific studies have documented growth spurts in both the coastal redwoods and giant sequoias.

Since the 1970’s, taking corings from trees more than 1,000 years old, scientists claim certain coastal redwoods have experienced the fastest growth ever. “The forests are not experiencing detrimental impacts from climate change” stated Emily Burns, science director at the Save the Redwoods League.

A variety of factors besides climate change could explain the increased growth rates said professor Stephen Sillett of Humboldt State, one of many researchers. Scientists established 16 research plots in old growth redwood and sequoia forests throughout their respective ranges. They took pencil width corings from 78 redwoods, studied the tree rings and developed a chronology dating back year 328. They also took corings from sequoias, analyzed the rings and dated the trees back to 474!

The data revealed redwood trunk growth in recent decades has “shattered” all records. The global warming records and effects on regional precipitation are less clear, indicating highly variable precipitation but overall no significant decline in the recent study areas. One theory is old giant sequoias might be growing faster because rising temperatures have extended the growing season in the Sierra Nevada.

Other theories include redwoods receiving more sun due to reduced fog in coastal climates yet still getting the precipitation they require or getting more sunlight due to a reduction in air pollution in north coastal areas from reduction in wood processing plants.

A great side benefit of the research was discovery of an ancient tree that corings revealed the oldest coastal redwood on record, 2,500 years old, besting the previous record holder by 300 years!!

When is comes to climate change, Professor Sillett added “I’m more worried about humans than I am about redwoods. I think they’re going to hold their own”. Very glad to hear this positive redwood assessment although a bit concerned about the human race.

Click to read the full article Is Climate Change Affecting Redwoods?

Oak Tree Failure Kills Counselor at Camp Tawonga

Camp Tawonga Tree Failure

My son Jake called yesterday very upset, telling me about an oak tree falling and killing a counselor at Camp Tawonga near Yosemite, CA.  My son graduated with a degree in Environmental Studies and Economics from UC Santa Cruz last June and worked the summer at Camp Tawonga.  He loved working there and returned for some part time work last fall.

What was chilling was his description of the exact location where the tree fell, he said he often sat nearby the spot and even sat under the tree!  He knew the counselor, Annais Rittenberg from UC Santa Cruz, where he also took the environmental field course his senior year.  Needless to say, he is shocked by what happened.

As a certified arborist, I provide tree risk assessments, a process of tree investigation and analysis that rates a tree defects and determines the hazard potential of a tree part or whole tree failure.  I have worked with plaintiff and defendant attorneys concerning tree failures and accidents, yet this accident struck very close to home.  I keep thinking about how that easily could have been my son under that oak tree when it failed.

Who knows if this failure could have been predicted?  My son mentioned how the area where the tree was located was irrigated daily throughout the summer, he said the tree trunk split and fell.  Was there root rot, cavities, or decay in the trunk?  Was the crown showing signs of stress?  Would a risk assessment have determined the tree was structurally unstable?  Maybe yes or no, I certainly don’t want to speculate, as I do not know the facts.

Tree failures resulting in human fatalities are very low, yet it only takes one failure to change lives forever.  My heart and sympathies to the family for the terrible loss.

This should serve as a reminder to camps, recreational facilities, golf courses, R.V. parks and manufactured housing communities to inventory and inspect your tree assets on your property, common spaces and even notify homeowners of endangered trees on their private lots or property.  Facility owners who take proactive measures to inspect, inventory, assess and maintain their tree assets increase the chance of detecting and minimizing tree related accidents before they happen.

 

Tree Risk and Premise Liability: Property Owners Beware!

Trees, Premise Liability and Risk Management

My appreciation for trees dates well back to my childhood days spent at summer camp and camping trips with my family. I still remember the distinct fragrance of the California Sycamore trees that provided shade during the summer camp months and wonderful Coast Live Oak trees encountered throughout California hillsides and campgrounds.

As a certified arborist, professional horticulturist, licensed landscape contractor and land development professional, my perspective on tree aesthetics and utility is now tempered by the business reality of liability and the risk trees create. An old specimen tree viewed from a liability perspective is a completely different experience than enjoying the historical or horticultural wonders the tree may present. In fact, when viewed from a risk management perspective, the same wonderful historical or landmark tree could pose a potentially serious safety threat or legal liability. Imagine the beautiful Coast Live Oak above in an urban setting with some of those branches hanging over a vehicle!

Premise Liability and the Property Owner

It is a property owner’s legal duty to maintain their premise in a safe, hazard free condition and that responsibility also applies to the trees on their property. Whether a homeowner, business, or homeowner association, an integrated inspection and maintenance program can reduce an owner’s exposure to expensive negligence lawsuits while improving the aesthetics and health of the overall landscape. Minimizing the potential harm or loss from a tree related accident is a proactive form of tree risk management.

There are two principle forms of risk associated with trees. Whether the tree is located in a public or private setting, there is potential risk for the tree to cause physical harm or property damage. Typically, it is the public at greatest risk for experiencing harm caused by a tree failure. There is also the financial risk borne by the Owner caused by the potential failure of the tree or tree part.

While many municipalities focus on the financial risk associated with tree failure, owners should focus on the risk of physical harm as the reason and foundation for developing an effective risk management program. Unfortunately, there are no existing inspection standards for tree hazard or risk management in the United States. Jurisdictions implement their own standards, trade associations such as the International Society of Arboriculture (ISA) and American Society of Consulting Arborists (ASCA) are working toward standardization of specifications, techniques, and risk evaluation, but it is still a matter for each property owner to monitor and care for their trees, preferably before they become a legal liability.

Tree Protection Plans During Construction and Development

In San Diego County there is a community that was developed in an existing and enhanced Eucalyptus tree forest. What appeared a great idea 30 or 40 years ago to create an urban Eucalytus forest surrounding a residential suburban community now appears to be a risk management nightmare as 100’ plus tall, 24”-36” diameter Eucalyptus trees drop limbs or suffer complete structural failure falling onto adjacent homes and unfortunately, killing and injuring the public.
In the past, when land was under mass development, existing trees were paid little attention other than objects to be removed during grading. In some instances, specimen trees may have been transplanted and relocated, trees retained in the landscape were usually neglected or had minimal devices installed to protect the tree during development. When a property is under development, the focus is on grading and infrastructure, utilities and street improvements, protecting existing trees is usually overlooked or a very low priority.

With time and recognition of the value and aesthetics trees create, development and politics have combined to create new incentives to preserves trees. The public clamors for “green” improvements in sustainability and now demands trees be retained and preserved. Unfortunately, in some cases the pendulum has now swung to the opposite extreme, whereby the public or property owner is insisting on preserving a potentially risky tree without realizing the potential consequences.

That is why it is imperative to protect and preserve existing trees in a construction zone to ensure their overall health and vigor during and after the construction process and to prevent the tree from becoming a future liability due to damage caused during construction. Most people might not notice symptoms of tree decline caused by construction activities. Without proper protection, tree roots may be damaged by soil compaction or grade change. Trees are often damaged by construction equipment striking limbs or scraping the trunk. Utility trenches cutting across or through root tree root systems seriously undermine the mechanical stability of the tree while compromising the trees ability to absorb water and minerals from the soil.

In instances where historic or specimen trees were retained in and around development, those trees eventually had to be removed due to declining health conditions and the increased risk these trees possessed. Had they been better protected during the development process, there would have been increased likelihood of successful retention of these valuable assets.

Managing Tree Risk Through Policy and Action

Let’s define a policy as a line of argument used to rationalize a given course of action. From an ownership standpoint, having a documented tree risk policy is extremely important. The policy provides a clearly defined direction and course of action for managing the risks associated with tree resources or assets. If a tree failure results in a legal action, having a documented policy is the basis for a legal defense. By having a tree risk management policy, Ownership demonstrates their legal duty to maintain their trees to protect the public and the actions they took to address the risk. Obviously, having a tree risk management policy is better than having no policy at all.

While a policy and procedures are best management practices for larger businesses and homeowner associations, an individual property or homeowner can benefit from a simplified annual inspection and maintenance program without having to have a written tree risk management program. By having a certified arborist inspect the trees annually and implementing the recommendations made in the inspection report, a property owner is demonstrating their duty to protect the public and reduce the risk associated with trees on their property. In so doing, the owner is building a basis for a legal defense in the event of tree related litigation.

Whose Duty is it Anyway?

Owners who think a tree failure is considered an Act of God as a defense will find this to be untrue. Courts across the country have found property owners have the duty to inspect, maintain and correct hazardous tree conditions that inhibit line-of-sight. There has been a natural progression toward statutes that deal with premise liability and the duties owed to guests and the public regarding “foreseeable” problems from trees.

Over time, the legal industry has worked to extend this duty or responsibility to developers, builders, property managers and other property professionals, including those who act in a property owner’s stead. If you work as an agent for an owner, you could find yourself having inadvertently taken on the “duty to inspect” and increased your exposure to a liability lawsuit.

The legal duty for property owners or those acting in their stead to protect visitors, workers, guests, pedestrians or vehicles from hazardous conditions exists in many states. Acknowledgement of this duty is witnessed in the daily maintenance activities and repairs made to fences, sidewalks, walls, gates, building edifices and more. Obstructions are cleared in sight line corridors to insure traffic flow and safety. In many states, the same duty to protect the public has been extended to trees and their appropriate maintenance requirements.

A routine annual tree inspection can in theory, be performed by anyone. However, many tree problems are difficult to detect and require a trained professional to identify hidden deficiencies. A knowledgeable arborist should perform a visual tree assessment, including tree identification, growth characteristics, size, tree biology, and site specific environmental influences. Most importantly is the risk evaluation of a specific tree branch, limb or complete tree failure and risk of harm to any surrounding potential target(s).

Managing Tree Risk

The tree above was a 10-ton Erythrina (Coral tree) that fell and crushed the car below. The tree was noted to have lost a limb earlier but was not properly inspected, nor was the risk abated. http://www.stuff.co.nz/auckland/470947

Trees pose a risk only when there is a target. A target can be a person, animal, property, vehicle; almost anything of value can be considered a potential target.
In the urban forest, trees are located in immediate proximity to people, buildings, vehicles, and countless moving and stationary targets. Sites requiring special attention due to increased risk include parks, schools and playgrounds, campuses, golf courses, athletic fields, and adjacent buildings. While the simplest means to reduce risk is to remove the target, that is not a practical reality in most urban settings. Therefore, an active risk management plan or policy will help reduce the risk of your trees causing a serious accident or injury resulting in a lawsuit.

  1. Schedule an annual visual tree inspection and hazard evaluation by a certified arborist.
  2. Implement the recommendations made in the inspection report.
  3. For larger properties, consider a risk management policy and program.
  4. For larger sites, implement a tree inventory log, noting identification, location, size, health and special characteristics of all site trees.
  5. Work with a certified arborist trained in visual tree assessment and tree hazard evaluation.
  6. Maintain written records, pictures and documents that support your efforts to maintain and protect the public from tree related hazardous conditions.

Conclusion

There are certain “red flags” used in visual tree assessment that you should be aware of. If you notice any of the following symptoms on your trees, contact a tree professional immediately:

  • Large holes, fissures and cracks in the tree trunk
  • Obvious areas of rot or decay including tree hollows
  • Presence of birds, insects, ants etc streaming into tree openings
  • Broken branches, dead and hanging limbs
  • Sucker or aberrant growth
  • Conks, mushrooms or fungi fruiting bodies at base of tree or on trunk
  • Any line of sight obstruction

Although a property owner may not want to know, thinking ignorance of a condition eliminates potential liability, our judicial system continues to find owners have a duty to inspect and maintain their properties and ignorance of a hazard is not an adequate defense.

The benefits of implementing an annual tree inspection and maintenance:

1. Increase in tree aesthetic appearance, health and vigor.
2. Increase in tree and property value.
3. Reduction in tree hazard risk.
4. Foundation for a legal defense.

An ounce of prevention is worth a pound of cure. Using a certified arborist for an annual tree inspection and monitoring program is an effective means to reduce tree hazard risk while improving the health and vigor of your investment. Just as you maintain your home, vehicles and other physical possessions, trees grown in the urban environment must receive the proper care and maintenance to keep them in a healthy, vigorous and safe condition.

Article Acknowledgments:
Mr. Mark Duntemann, Natural Path Urban Forestry, Seminar on Tree Risk Management, August, 20, 2010.
Premise Liability and Your Trees, by Petger S. Beering, Esq. and Judson R. Scott, RCA #392, American Society of Consulting Arborists, #3, 2010

Unsure of What Plants to Select for Your Landscape or Garden?

The Basics on Landscape Design, Tree and Shrub Selection for Southern California Landscapes

 
I am most definitely a native SoCal.  Born in the San Fernando Valley in Los Angeles, educated at UC Santa Barbara and California Polytechnic University, living in San Diego for many decades, I have lived in Southern California my entire life.
 
Yes, we complain when we have hot spells, (last summer was ridiculous), Santa Ana winds, and the fog, but overall, we have the best climate in the world for growing plants.  Whether for ornamental landscapes or vegetable gardening, we a blessed with a climate and environmental conditions that allow us to grow an incredible variety of trees, shrubs, ground covers, turf, vegetables and fruits pretty much 365 days a year.
 
Walk or drive throughout our neighborhoods and check out the incredible plant diversity.  We are very accustomed to the trees and plants that surround us.  However, if you are from the midwest, east coast or other parts of the country or the world, you are most likely amazed at the variety of plant material.  Botanical gardens and arboretums from Santa Barbara to San Diego boast incredible displays of plants from around the world that flourish in our mild Mediterranean climate.
 
We have neighbors recently moved to San Diego from Kansas City.  They purchased a home and want to landscape but are completely baffled about what to plant.  Obviously, the trees and shrubs they were accustomed to in Kansas City were very different from what is available for landscaping in San Diego.  I offered some suggestions to help simplify the plant selection process.
 
There are many approaches one can take to designing and installing an ornamental landscape for their home or place of business.  Using a landscape architect to design a planting and irrigation plan is an excellent choice, however it can be costly.  Landscape contractors can provide design services as part of a design build contract, however you might feel uncomfortable about possible conflict of interest, and whether the contractor is truly knowledgeable about plant material and design.  Then, there are the millions of property owners trying to do it themselves.  This article is for you!

Where to Start?

Don’t get caught up with or distracted by endless design themes and details.  If you have a certain theme in mind, fine, then you most likely already know the kinds of plant material you want to use.  I prefer to design and select plant based on the site environmental conditions matched to the cultural requirements of each plant to be used in the landscape.  What does that mean?

What are Environmental Site Conditions?

The first step in selecting plant material is determining your specific site conditions.  There are many factors that affect plant growth and they are reflected in your site.  Analyze your location and be able to answer the following questions:

  1. Does the site face the north (full shade), east (part shade part sun), west (part sun – full sun), or south, (full sun).  Determining the site sun exposure is one of the most important environmental conditions.
  2. What are the temperature extremes.  Does the site receive cold weather extremes such as frequent frosts, freezes, snow or hail?  Does the site receive intense heat?  Determine the temperature extremes as well as the average seasonal temperature for your location.
  3. Is the site near the coast where it will receive constant salt air and sea breezes?
  4. Is the site windy, contain microclimates, protected by a structure?
  5. Is the soil a heavy, poorly drained clay or lighter, well drained loam, or sand?
  6. Is the soil structure friable and fertile or dry and compacted?
  7. Does the site drain well or is water trapped onsite or on top of a perched water table or spring?
  8. Are there rodent or pest or disease problems?
  9. Are there physical site constraints such as overhead or underground utilities, concrete or masonry improvement?

 
These are just a sampling of typical environmental site conditions that affect plant growth.  The more you know about the site to be landscaped, the better informed you will be in order to make appropriate plant selections.
 
In the next installment, I’ll discuss plant cultural requirements and the importance of selecting plant material with cultural requirements that match the site environmental conditions, a key to successful landscape project!