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.

Oak Tree Failure Kills Counselor at Camp Tawonga

Posted on July 4, 2013 by landscapeexpert

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.