The beauty of spring is all around us, take a moment to enjoy it. Take a walk through any of our coastal canyons, parks and open spaces. You’ll be rewarded!
Back in my college days at Cal Poly Pomona, I took several plant identification courses as part of the educational requirements for Ornamental Horticulture. Two trees from the same genus always stood out for their outstanding floral display and landscape use. Back then, the genus was called Tabebuia, since changed to Handroanthus. The two useful landscape species are Handroanthus impetiginosa,(Pink trumpet tree) and H. chrysotrichus, (Golden trumpet tree).
While taking a walk, I came across a beautiful pink trumpet tree in full bloom. I then started noticing a few other trumpet trees scattered about the neighborhoods in North Park. I’m not to sure why, but in my view, this species is an under utilized ornamental landscape tree. Perhaps due to a slow growth rate, medium appetite for water or its deciduous nature, the species is not heavily promoted by the nursery industry. But it has many beneficial characteristics making it a useful ornamental landscape tree.
The pink trumpet tree requires full sunlight to part shade and grows to approximately 25-feet in height in Southern California. The non-aggressive rooting system makes it a good choice for use in smaller confined planter areas such as a parkway strip. It performs well in the urban environment. Like most trees, it prefers well drained fertile soils however I see this tree flourishing under less than ideal conditions. No noted pests or disease, hardy to 24º F, damaged below 18º F. After spring flowering, it grows a green to brown colored pod.
Unlike the pink trumpet tree, the closely relate golden trumpet tree is a more rapid, larger growing tree. It too is deciduous, and like the pink trumpet, it flowers in the spring with an impressive display of brilliant, fragrant yellow trumpet flowers.
This tree grows to a larger size than the pink trumpet, up to 50-feet tall and similar width. It has a spreading, low canopy that matures into a broad, round-headed or vase shaped crown. It prefers full sun to part shade.
Branch strength is rated as medium to somewhat weak and root growth is more aggressive than the pink trumpet. Unlike the pink trumpet, the golden trumpet tree should not be used in a confined planter are.
Both these trees perform well in our mediterranean climate and their different growth characteristics allow for varied use, one in more confined areas, the other requires more room to grow. Once established, both are relatively drought tolerant.
Hope you find this helpful, let me know if you have any questions!
We have gone from record drought to record amounts of snow and rain throughout California. While the winter storms have wreaked havoc on our infra-structure (Oroville dam spillway, flooding in San Jose, etc, they have been a blessing for drought starved trees throughout the west. Years of inadequate rainfall reduced soil moisture leading to an incredible dieback of trees numbering over tens of millions within the state.
The urban environment creates stresses not normally encountered in the wild. In cities and suburbs, trees contend with confined planter area, compacted soils, improper or inadequate irrigation, poor maintenance practices, improper pruning, shading by homes or buildings. Stresses created by the urban environment reduce tree life expectancy, sometimes by as much as 50%.
During the drought, I have seen an increase in tree failure, whether a limb drop or whole tree failure. In most instances, crown, limbs, branch and twig dieback were the obvious symptoms of the drought. Many times, clients mistakenly thought the dieback was caused by disease or insect, however root dieback from minimal soil moisture was the cause of crown dieback.
Now, with the heavy rainfall and wind, tree failure due to saturated soils are on the increase. Trees remain upright due to their root system. Structural and buttress roots grow outward from the trunk at the (root crown), out to the edge of the crown (known as the dripline). At the dripline, the structural roots are 1-2″ in diameter. They continue to grow outward, branching into the small, fine feeder roots that absorb moisture and nutrients. Depending on local conditions, tree roots may extend 1.5 times the tree crown diameter. Based on San Diego soil conditions, most roots grow within the upper three feet, typically 80% of the roots are within the top 18-24″ of the soil.
Roots in dry soil are held in place by friction. However, when rain saturates the ground, it acts as a lubricant, lessening the soil friction holding roots in place. When wind combines with excess weight from rain or snow, the energy is transmitted down the trunk to the roots. Soil root friction reduced by saturation causes roots to loose anchorage, resulting in a failure. When roots fail to support the tree, it is assessed as a root failure. When the entire root ball rotates up from the soil, it is a soil failure.
Homeowners with large trees in close proximity to their property should examine their trees for any change in condition as a warning sign of a potential problem. Changes to be aware of include:
- Is the tree leaning?
- Are there soil cracks at the base of the tree?
- Is the soil lifting, tilting or rippling at the tree base?
- Are there dead limbs or branches in the crown?
- Is there a progression of twig, branch and limb dieback?
- Did the tree drop it’s leaves abnormally early?
- Did the tree not leaf out as in the past?
- Any obvious open cavities, cracks or splits?
- Any animals or insects nesting within a hollow, cavity or crack?
- Any fluids, abnormal sap flow or other discharges from the tree?
- Has irrigation been reduced or eliminated to the tree?
- Has there been construction activity near the tree?
- Have the roots been disturbed by any nearby utility or sidewalk work?
- Is the tree sitting in water, is there proper drainage?
- Has there been a change in grade near the tree?
If you can say yes to any of the above, your tree may have acquired defects that increase the risk of failure. The increased risk of failure may result in property damage or personal injury to your family, friends, or any pedestrian near the tree. A tree with a history of previous failures possesses an increased risk of failing. Trees may not present any obvious signs or symptoms of a defect. Unseen decay may exist within a limb or trunk, or as a root rot.
Whether commercial or residential property, if you are concerned about the health and safety of your trees, you should contact an arborist certified by the International Society of Arboriculture, (ISA). Once certified, the ISA allows arborists to enroll in specialized training to earn the credential of a Tree Risk Assessor Qualified. While anyone may attempt to assess the health and structural integrity of a tree, certified arborists who are qualified in tree risk assessment represent the industry standard and best management practice for tree risk assessment.
Tree risk assessment is the current best management practice to determine tree risk of failure associated with defects. The assessment utilizes a level two basic visual assessment and a two page ISA format for the assessment protocol. The assessor may determine more advanced assessment techniques are required, however usually a basic visual assessment will suffice.
If you have noticed a change in the health or condition of your tree, take proactive measures before a catastrophic accident, call a certified arborist knowledgeable in tree risk assessment.
Click here to read an article published in the LA Times Risk Assessment article.
Such a gorgeous spring day, had to go for a walk through Morley Field and Balboa Park. I knew it would be a busy day with lots of people seeking the beauty and sunshine at the park, so I decided to walk through some of the less visited areas of the park in search of plants.
When your a horticulturist, arborist, landscape contractor and avid gardener, it is kind of a curse and a blessing. I cannot help but be drawn to looking at trees, shrubs, landscape design and contrasting plant foliage and flower colors.
I took a bunch of pictures, some might seem more obscure or leave you wondering what the heck that plant is! Take a moment and enjoy!
Cactus, succulents and natives at Balboa Park
In May and June of 2015, The Los Angeles Times published articles addressing the problem of crumbling sidewalk infrastructure within the City of Los Angeles. The articles focused on the challenges pedestrians face in this car-dominated city. After years of mounting complaints and lawsuits caused by defective, dangerous sidewalks, city officials are finally beginning to address the problems caused by trees that were planted within city parkways, medians and right of ways.
After decades of deferred maintenance, the City Council, the Mayor, and public work officials are finally turning their attention toward addressing the problem, and trying to figure out how to juggle spending requirements resulting from legal settlements and sort out who is responsible for future sidewalk maintenance, as well as liability for future injuries caused by damaged sidewalks.
The first question, who is responsible for sidewalk repair and replacement caused by trees growing within city parkways and right of ways? California state law placed the burden of sidewalk repairs on adjacent property owners. A majority of California cities adhere to the state policy, however not the City of Los Angeles, which forty years ago opted for a policy that made the City responsible for repairing sidewalks damaged by tree roots in city parkways. Back in the 1970’s, when federal funding was available for the work, Los Angeles opted to pay for tree-damaged sidewalks. When the federal funding was depleted, voters declined to support tax increases for the repair work, leading to the current massive backlog of damaged sidewalks.
Instead of removing invasive, surface rooting tree species and replacing damaged sidewalks, the city embarked on a less expensive program of temporary asphalt patches in an attempt to smooth over displaced, uneven sidewalks. The problems continue to mount, with over 19,000 sidewalk complaints within the past five years alone. Over 40% of the complaints have been ignored, with no repairs having been made, mainly due to inspections never being made or the sidewalks so severely damaged they require complete rebuilding.
The City is now proposing a policy to address the situation. Under the proposed policy, neighborhood sidewalks damaged by city parkway trees would be replaced at the city’s expense. However, after repairs are completed, responsibility for repair, maintenance and liability would be shifted upon the adjacent property owner.
The proposal has received mixed comments from residential and commercial property owners. Businesses already pay taxes they assume local government should be using for infrastructure repairs. Additionally, requiring businesses to pay for repairs would harm retailers, especially in districts lined with problematics trees. Many commercial property owners would be forced to pass on the expense to the small business owners that rent the property.
Under the “fix and release” program, repairs would be made by the city, and then future responsibility for the sidewalks transferred to the homeowner. Some homeowners feel this would be an equitable solution to the current problem, other disagree, stating they would be saddled with big bills down the road, particularly if the city does not fix the “root” cause of the problem, that being tree roots or leaking utilities.
The city must grapple with both sides of a delicate issue, trying to preserve the benefits of large, picturesque trees providing neighborhood character while having to remove the same trees whose invasive roots have damaged infrastructure and would continue to do so if left in place. To begin the process, the city acknowledged they do not really know how extensive the problem is. The city has no existing tree inventory of the tree and sidewalk condition. Without this information, it would be difficult for the city to measure progress as they attempt to implement any new sidewalk management policy.
Certified and registered consulting arborists consult with Southern California municipalities and private property owners involved in trip and fall litigation caused by tree root lifted and damaged sidewalks. Typically lifted and damaged sidewalks caused by tree roots are due to inappropriate tree selection. Species such as Sycamore, Ficus, Eucalyptus and Ash trees planted decades ago in restricted parkway planters were most often associated with damaged infrastructure.
Sidewalk repair or replacement without addressing the existing tree species ignores the problem. Passing on responsibility for future repairs and liability to adjacent property owners would be an unjust situation for taxpayers. Large, surface rooting, invasive species should be closely examined for mitigation in conjunction with infrastructure replacement. Perhaps root pruning and root barriers might be an appropriate remediation that would protect future infrastructure while retaining large pre-existing species.
However, many species planted decades ago were and will always be inappropriate for confined parkways. Root pruning a large Ficus or Sycamore could easily de-stabilize the tree, resulting in a catastrophic failure. Who would be liable for a tree failure and resultant property damage, or worse, personal injury or death? Citizens might have to accept they cannot have the best of both worlds, where large, invasive trees are retained for neighborhood character, sidewalks are repaired and the city remains responsible.
Over the decades, many newer street tree species have been developed that provide desirable growth characteristics while minimizing damaging invasive root systems and towering canopies that conflict with traffic and overhead utilities. Reasonable compromises can and should be made toward replacing older, inappropriate tree species with newer species that will provide community benefits while minimizing maintenance costs and damaged infrastructure.
Hopefully, the City of Los Angeles and other municipalities facing this problem elect to use certified and registered consulting arborist and horticulturists as they consider how to address their urban forest and infrastructure issues.
To read the full Los Angeles Times Article, click the link:
I have been getting an increased number of calls from people concerned about their tree(s) starting to dieback. They want a certified or registered consulting arborist to evaluate the tree health condition, determine the cause of the tree decline, and recommend treatment options or removal.
For the past two to three years, I have noticed the increasing number of declining trees throughout San Diego. Especially noticeable is the tree dieback in the backcountry as well as local canyons and open spaces. Even drought tolerant Eucalyptus, Oak and Pines trees are struggling to survive.
The cause of our tree decline and dieback is the ongoing California drought. With yet another year of little winter rain, soils throughout San Diego county have little moisture reserve remaining. The drought is affecting native as well as ornamental trees used in the landscape.
Indeed, certain trees in our area are struggling due to insect infestation. The gold spotted oak borer attacking Coast Live Oak, as well as a host of ornamentals including Olive and Liquidambar trees have been infected with fusarium vascular disease introduced from borer and insect infestations. Therefore, it is not uncommon for most people to assume their tree must be declining due to some kind of insect or disease.
I have observed people rarely consider the effect of the drought as being the primary cause for tree decline. The tree living in the back yard or slope area for the past several decades may be dying simply because there is no more water in the soil profile! Even the deepest rooted trees cannot survive accumulated years of consecutive drought.
I recently received a call from a gentleman complaining his fifty year old Jacaranda tree was dying. The new foliage had germinated then died back, now small twigs and branches were dropping. The bark on the trunk was exhibiting uncharacteristic roughening. The tree was located at the bottom of a slope near a turf area. Months ago, the turf sprinklers had been turned off, now the tree was struggling to survive.
Tree roots seeking moisture grow well beyond the drip line of the tree crown. Under drought conditions, soil moisture is not being recharged from winter rains. Unless a tree is receiving supplemental irrigation, it is reliant upon finding soil moisture by growing into irrigated turf and planter areas.
With increased water restrictions and rates, people are reducing or eliminating irrigation to their lawns and shrub beds without considering the effect on nearby trees. Trees that adapted their root systems to getting water from nearby irrigated areas that no longer get watered will begin to decline as the remaining soil moisture is exhausted.
A tree weakened by drought becomes increasingly susceptible to secondary pest or disease infestations. Many beetles can detect stressed trees from miles away. However, attempts to eradicate secondary insect infestations will not resolve the underlying cause of the tree decline.
So, if you notice your tree starting to decline, here is a brief check list of considerations:
-Is the tree irrigated or non-irrigated?
-If non-irrigated, does the tree get water from a nearby irrigated source?
-Has there been recent re-programming or turning off the irrigation?
-Any recent construction or trenching nearby the tree?
-Any grade change such as fill soils placed over the tree roots or cuts?
A well maintained, mature street tree in the front yard of a property may add an additional 7% to the assessed value of a property, a dead or declining tree obviously reduces street appeal and real estate value. Trees can be retained and successfully survive the ongoing drought, contact a certified or registered consulting arborist to provide a tree health evaluation and recommendations on how to protect your tree investment value.
The Professional Tree Care Association (PTCA) of San Diego hosted their annual seminar and field day, a two day event on Friday, August 22 and Saturday August 23, 2014. This was the 25th annual event and like many of the previous seminars, this was another informative, educational experience bringing together a wide diversity of speakers and audience!
The seminar was on Friday and this years theme centered on the ongoing California drought and ramifications to trees. There were a number of great speakers, starting with Mr. Ron Matranga who provided an overview about trees in times of drought, current and future water restrictions . Dr. Roger Kjelgren, Professor from Utah State University, provided a simplified method for landscape irrigation demand estimation. Dr. Linda Chalker-Scott, the Urban Horticulture Extension Specialist from Washington State University discussed how to treat and avoid drought stress in landscape trees and Ms. JoEllen Jacoby, the Water Conservation Landscape Architect for the City of San Diego enlightened us about planning for current and future water restrictions (gulp, better get some rain this winter)!
Ms. Mary Matav, Agronomist from Agri-Serve presented information on how to combat pests and drought, followed by Dr. Tracy Ellis, Entomologist with the San Diego County Department of Agriculture, scaring all of us about tree insect interceptions and quarantines in San Diego County.
A great roster of speakers who delivered relevant information in a beautiful setting at Balboa Park in San Diego. On Saturday, the event transferred to the field, where information discussed at the seminar was applied and viewed in the field, an aspect of the field day I find very beneficial.
As usual, Dr. John Kabashima, the Environmental Horticulture Advisor with the UC Cooperative Extension, presented new, current information on the latest insect threat to our ornamental and agronomic trees in California, that being the Polyphagous Shot Hole Borer, (PSHB). As many of us already know, this destructive ambrosia beetle is now active throughout the Southern California.
The PSHB is an invasive ambrosia beetle that carries the fungus Fusarium euwallaceae. The female tunnels through the bark and lays galleries of pre-fertilized eggs and grows the fungus, which becomes food the newly hatched beetles. The fungi infects the tree with a disease called Fusarium Dieback (FD), which interrupts the transport of water and nutrients through the vascular system of the tree. In essence, this is a vascular clogging disease resulting in dieback and death of a large host of trees. Unfortunately, there is no cure at the present time and beware of PSHB/FD look-alikes. Here is very informative attachment Dr. Kabashima provided that really provides current information about this insect. Handout is published from the University of California and the UC division of Agriculture and Natural Resources. PSHB Information
Many thanks to all of the hardworking voluntary staff of the PTCA. What a great local association, I am very proud to be a member of. The PTCA is an active association promoting the best in tree care and tree knowledge. An association composted of tree care companies, certified and consulting arborists and tree care professionals, the PTCA continues to provide current and relevant topics for it’s membership and community at large. Thanks again PTCA, looking forward to next years Seminar and Field Day!
Rappoport Development Consulting Services LLC has been hired by the City of San Diego to provide certified arborist consulting services for the North Torrey Pines Road Median and Street Enhancement project. Estrada Land Planning Inc., the project landscape architectural firm, has sub-contracted with RDCS LLC to implement tree protection plans, including tree monitoring, and best management practices. Tree protection plans and best management practices (BMP’s), are designed to minimize construction impacts to the existing median and parkway street trees.
The project encompasses approximately 1.5 miles of construction work along North Torrey Pines Road, adjacent to the Torrey Pines Golf Course. The scope includes street improvements (curb, gutter, guardrail, sidewalk, drainage) as well as landscape and irrigation within the medians and parkways. Palm Engineering is the General Contractor for the project.
Within the project boundaries, north and southbound traffic is separated by a median, varying in width from approximately 3 to 20-feet. The current median landscape consists of moderate to large size Eucalyptus trees with no other understory planting. Previously, RDCS LLC was hired as a certified arborist sub-consultant by Estrada Land Planning to develop a tree inventory for a sensitive portion of the project.
The inventory included tree health and when needed, tree risk assessment to determine if certain tree defects created hazardous safety conditions warranting removal.
The trees inventoried were primarily Eucalyptus cladocalyx, commonly known as the sugar gum. Smaller caliper trees ranged in age from 20 to 30 years old, while larger trees possibly up to 100 years old. The existing Eucalyptus median trees have grown and acclimated to the site conditions, under non-irrigated conditions. Preparing the trees to survive through the construction process is extremely important. The three parts of the tree requiring protection include the tree crown, tree trunk and tree roots.
Jeremy Rappoport, President of RDCS stated,
“We knew we would encounter tree roots throughout the median, our goal was to minimize root conflicts and environmental stresses to the trees.” Therefore, tree protection best management practices included aerial canopy pruning to remove deadwood from each tree crown, installing construction fencing to protect tree trunks and hand trenching and root pruning to minimize roots conflicting with street improvements.
The concept of root pruning is to trench and locate conflicting roots and hand cut them rather than having a piece of grading equipment ripe or tear the root out of the ground. Hand trenching and root pruning reduces the shock and destruction of small absorbing root hairs caused when heavy equipment rips, tears or cuts roots. Properly implemented, root pruning is an effective arboricultural technique to reduce construction impacts to tree root systems.
Best management practices also include reducing soil compaction by minimizing construction traffic and not allowing staging or parking equipment underneath tree canopies. Although the site is not irrigated, recommendations for weekly construction watering were implemented to help the trees cope with the stresses caused by the construction work.
RDCS will provide consulting services whenever construction work endangers the existing trees. Rappoport stated “We were told to be on call for monitoring services during certain phases of the street improvements and trenching. We have completed the first phase of canopy pruning and expect to provide root pruning on certain trees in the near future”.
Rappoport Development Consulting Services LLC provides certified arborist consulting services for infrastructure projects. Certified arborist-consulting services include tree inventories, tree monitoring, tree construction protection plans and best management practices, tree risk assessment, tree health assessment, tree and landscape appraisal services. Mr. Rappoport is an International Society of Arboriculture certified arborist and certified tree risk assessor, a C-27 California Landscape Contractor and a professional horticulturist. For decades, Mr. Rappoport worked for public and private master sub-division builders as a landscape and grading superintendent, manager and director of land development. More information is available at https://landscapeexpertwitness.com/.
This past summer brought us the gigantic Rim fire that devastated Yosemite National Park and surrounding communities. Over 4,900 firefighters operated under a unified command, however when the fire crossed over into the boundary between state and national park land, the National Park Service took a very different approach than Cal Fires (California Department of Forestry and Fire Protection). Continue reading “Let it Burn or Suppress It? US Park Service vs Cal Fire Policy” »
Fortunately, most municipalities now have recycling programs for green waste, making it easier for homeowners to recycle their used Xmas tree. Recyclers grind or shred trees into a mulch which is then composted and eventually becomes available as a bulk or bagged mulch product. This is certainly a preferable option than the “old days” when trees were commingled with regular trash and buried in landfill sites.
If you have a large tree, prune off some branches and reduce the overall size to ensure local curbside pickup. If you have the room on your property, you can do your own recycling via a compost bin, pile or simply leaving the tree in an area where it will slowly decompose on its own. Leaving a tree whole may also become home to birds and other animals for shelter or nesting site. Make sure all tinsel and other decorations have been removed from the tree.
If you have a live tree, it can be re-planted into the outdoor landscape. Remember, depending on the variety of pine tree, these are typically large growing trees. Despite the small size now, ten to twenty years down the road, you may have a forty to sixty foot tall tree. I have seen this issue while consulting on residential sites where a neighbors Xmas tree planted near the property line grew to fifty-five feet, with limbs and roots encroaching into the clients property, damaging concrete improvements and posing an increased safety risk. If you are going to re-plant the tree, make sure you have the space for a large pine tree to grow, avoid planting near property lines, driveways, sidewalks and patios.
For more information about Xmas tree recycling, check out this article at: