Finally, A Turf Block Driveway With Thriving Turf!

Posted on June 23, 2020 by landscapeexpert

Rarely have I seen a successful turf block driveway. Turf block, turf stone, turf pavers are systems installed as living turf driveway alternatives. The material provides structural support via plastic or concrete cells that are filled with a soil media for turf installation. The block is designed to support vehicular traffic on driveways while providing a green alternative to concrete or asphalt driveways.

Turf blocks have been used for decades, but rarely have I seen thriving turf grass within the block. Not because of the product, but usually due to turf establishment and failure issues. Due to reduced soil root area, soil compaction, irrigation infiltration and damaged soil structure result in poor turf establishment. Soil preparation, drainage and proper irrigation coverage and operation are required to grow turf inside of a turf block system.

Lastly, using vigorous, warm season turf grasses that spread by horizontal solons, rhizomes, and rooting improves the successful establishment of turf grass, such as the Tiff hybrid Bermuda grasses developed for sports fields. Cool season turfs including rye, bluegrass and turf type fescues are clumping turfs that do not spread horizontally, thereby limiting establishment and healthy growth. Cool season grasses are more susceptible to leaf and soil borne diseases, are easily stressed during hot summer months, nor are they tolerant of vehicular and pedestrian traffic and compaction conditions.

Tiff hybrid Bermuda is well established within the turf block

Trip, Slip and Fall Hazard: Hidden Depressions in Grade

Posted on May 19, 2020 by landscapeexpert

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.

Old Growth Redwood Destruction Continues

Posted on April 21, 2020 by landscapeexpert

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?

Posted on April 14, 2020 by landscapeexpert

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

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

Posted on December 3, 2018 by landscapeexpert

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.

One of the Best Flowering Trees!

Posted on March 30, 2017 by landscapeexpert

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).

The Pink trumpet tree in full bloom

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.

A close relative to the pink trumpet tree but faster growing. By M.Ritter, W. Mark, J. Reimer, C. Stubler

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!

Removing Your Turf and Sprinklers Due to Drought, Remember the Trees!

Posted on May 18, 2015 by landscapeexpert

As Californians scramble to find a way to reduce water consumption to meet a 25% water reduction mandate, turf removal has become the latest means to accomplish significant water savings. From Santa Barbara to San Diego, with Los Angeles and Orange county in between, turf is being ripped out at a frenzied pace.

Considering the rebates offered by the Metropolitan Water District in Los Angeles and other municipalities, homeowners and businesses are jumping at the opportunity to be reimbursed for turf and spray irrigation removal. Succulent gardens, Mediterranean, and California natives and other drought tolerant plant materials are being used to replace water guzzling turf.

The decades long love affair with our green turf lawns is coming to an end. Unless you can afford to pay extremely onerous penalties for excessive water use, the California drought, climate change and dwindling water resources will change the way we design, plant, irrigate and use our landscaped areas.

As turf and spray irrigation is removed, it is easy to forget about trees in the landscape. Trees planted in the landscape rarely receive irrigation dedicated to just the tree. Typically, the tree is located in an irrigated turf or planter area. Tree roots grow where there is moisture. Trees adjacent to an irrigated turf area will certainly root into the turf zone because that is where the water and nutrients are.

A common misconception is trees develop deep tap roots that grow deeply into the soil to locate water. In fact, almost all tree roots grow within the top three feet of the soil mass, almost 80% of the roots grow within 12-24 inches from the soil surface! Initially, a tap root growing downward will encounter rocks, hard pan or other physical impediments causing the tap root to split into a fibrous system growing horizontally through the soil profile.

As roots grow outward from the trunk, the tree crown grows in conjunction with the spreading root system. The outward edge of the tree crown is referred to as the drip line of the tree. The structural tree roots grow outward toward the drip line, however they don’t stop there! Outside of the drip line, the structural roots become increasingly smaller in diameter and that is where the fine absorbing root hairs are located, often well outside of the tree drip line. Many tree species grow roots up to twice the tree crown diameter!

Knowing how tree roots grow is vital to understanding how your trees will react to changes in irrigation caused by converting turf or high water use areas. If the edge of a tree crown or drip line is near an irrigated turf area, it most certainly will have rooted into the turf soil zone. When the turf is gone and water is turned off, the tree will have lost it’s primary source of water and nutrients and will begin to decline. If it does not have or develop other water resources to tap into, the tree will eventually die.

If you notice the crown of your trees declining, not leafing out or new buds dying back, these are symptoms that may be caused by the affects of drought or lack of water. Think back and consider what changes have occurred in the past one to two years? Has there been construction or renovation work nearby? What about changes in the landscape, was the turf removed and sprinklers turned off? Was there trenching, rototilling or soil preparation in an area nearby existing trees?

You can still remove your water consuming turf and use drip irrigation, just remember to plan for irrigating the trees. If using a drip system, consider using higher volume emitters, or other distribution systems that will provide an adequate water supply to the tree. Add a drip valve solely dedicated to tree irrigation separate from the other shrubs or ground covers. Proper planning, installation and maintenance is required to convert water consuming landscapes into sustainable, water efficient landscapes while preserving existing tree health and aesthetics.

With proper planning, trees can be grown and will flourish using drip or low volume irrigation systems but you must provide enough water distribution to encourage the tree to root into the surrounding site soil. Unlike spray irrigation, drip systems must be maintained and upgraded as trees grow larger root systems. Additional drippers or emitters are required as the tree crown increases in diameter. Drip and low volume distribution systems work great but are more labor intensive than spray systems and require a higher degree of maintenance.

So go ahead and get rid of that old ugly bermuda grass lawn, or grit your teeth and say goodbye to your green lush tall fescue or Kentucky bluegrass and say hello to water savings without sacrificing visual aesthetics. You can keep your trees alive and flourishing while still achieve water savings and a unique, beautiful landscape. Use a landscape and certified arborist tree professional to help you achieve your sustainable, affordable landscape!

A Better Way to Protect Trees and Pedestrians

Posted on November 11, 2014 by landscapeexpert

Safe Path permeable product replaces cast iron tree grate

Through a business acquaintance, I had the good fortune to meet with Mr. Christian Rodriguez, a company representative from Blue Drop, Inc. We met at a downtown San Diego street intersection where Blue Drop, Inc. had a contract with the City of San Diego to replace old cast iron tree grates with their new product called Safe Path.

Tree planters within pedestrian sidewalks are typically small confined spaces surrounded by concrete with lots of pedestrian traffic. Tree grates were installed around the planter pit primarily to protect people from tripping over tree roots. The grate also allowed watering to occur beneath the grate and afforded the tree a degree of root protection from pedestrian traffic.

When first installed surrounding a young tree, there is plenty of room for the tree trunk and root collar to grow and expand. Tree grate openings typically are up to 12″ in diameter.

Tree trunk lifts grate creating potential trip and fall hazard

A young tree with a two inch diameter trunk will add one inch of trunk diameter per year. The tree will outgrow the tree grate opening within a decade. Just as the tree reaches maturity and is starting to provide the maximum intended benefits, the trunk begins to lift the tree grate. Either the tree or tree grate must be replaced.

When I met Mr. Rodriguez, he showed me a downtown site where Blue Drop had installed their new Safe Path product. The product is a poured in place permeable rubberized material that levels the planter surface with the adjacent sidewalk. Water quickly infiltrates the permeable product which allows for both water and gas exchange. The tree trunk, root collar and any surface roots are safely protected by the product. As the trunk and roots enlarge, the products cracks, allowing for easy product removal and mending.

Pedestrians safely travel over Safe Path tree system. Photo by Blue Drop

Because Safe Path is poured in place, it appears to be an ideal product to retrofit existing planter systems and especially for irregular shaped planter areas. The product provides a smooth, yet permeable surface, creating a safe environment for pedestrians while protecting tree roots and enhancing street scene aesthetics

I have no financial of special interest in Blue Drop Inc or any of their products. As a certified arborist who has provided expert witness testimony in trip and fall cases involving trees, I was interested in discovering new technologies that improve public safety around trees.

Click the link to read the full article reviewing the product. A Better Way to Protect Trees and Pedestrians

What to do With Your Xmas Tree?

Posted on December 26, 2013 by landscapeexpert

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:

Making the most of the Christmas Tree

Can a Tree Capture Particulate Matter from the Air?

Posted on November 26, 2013 by landscapeexpert

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.

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

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