CITYWIDE ‚Äî As city officials continue their investigation into the extent of alleged defects in the city‚Äôs urban forest, arborists point to nurseries as the possible root of the problem.
Members of the Urban Forest Task Force raised concerns about the health of trees after a city arborist noticed that newly-planted trees were dying.
He fired off a letter to the District Attorney‚Äôs Office alleging that a company contracted by City Hall to plant and care for trees on public property had purchased bad trees with the intent of charging the city to replace them.
Subsequent reports commissioned by City Hall indicated that a number of factors have conspired to damage those trees, but arborists throughout the industry believe that nurseries, in particular, hold much of the blame.
Nurseries are accused of poor propagation practices that maximize profits while damaging the health of the specimens.
Arborists say the businesses treat trees like product, keeping young trees in pots far longer than intended in order to minimize the amount of space they take up.
That can lead to problems with roots that grow to the shape of the container, potentially cutting the tree off from needed nutrients and years from its life.
If those trees get pushed off on cities or other customers who buy in bulk, bad stock could be doomed to failure before it ever gets planted, the theory goes.
Nurseries also tend to grow trees with slender stems because the plants are crowded and require support from stakes in the ground, said Donald Hodel, environmental and horticulture advisor for the UC Cooperative Extension of Los Angeles County.
“That doesn‚Äôt mean they can‚Äôt be planted, but it means that whoever is planting them has to be careful,” Hodel said. “There are remedial things that they have to do to help correct the problems.”
Hodel inspected trees in Santa Monica at the request of West Coast Arborists, the company that is paid millions by City Hall for tree care and planting, in December and January.
In a report dated Jan. 10, Hodel reported that trees planted by the company in recent years “are adequate and typical of industry trees for this period.” Some trees could benefit from some minor corrective pruning and others had post-planting issues but that “wholesale condemnation of these trees is simply unwarranted.”
David Cox, chairman of the California Association of Nurseries and Garden Centers and CEO of L.E. Cooke Co., a nursery in Visalia, Calif., acknowledges that nurseries have sold problem trees, but that many tree failures have more to do with what happens to the plants after they leave for their new homes.
Installers, as he calls them, have a responsibility to help trees out by cutting circling roots so that they have the ability to grow out normally, part of the “remedial work” to which Hodel referred.
Even those who claim decades of experience run into problems when it comes to the details like cutting the root ball, preparing the canopy or even planting the tree at a proper depth, Cox said.
“I‚Äôm not saying that nurseries are without blame, and there are probably trees that have been planted that shouldn‚Äôt have been,” Cox said, “but the installer should have caught that. If there‚Äôs a major flaw in the tree, they should know not to plant it.”
City arborist Robin Beaudry said he raised concerns about sub-par trees being planted but was ignored by city officials, which led him to file the complaint with the county‚Äôs Public Integrity Division, which investigates corruption and the misuse of public funds.
Other problems frequently pop up, like death by overwatering. Those inexperienced in tree care often mistake browning leaves with thirst, leading them to pour more water onto the roots of the young tree which can crowd out oxygen and lead to disease, Cox said.
Other circumstances beyond anyone‚Äôs control may also have impacted the quality of trees coming into the city.
The problem with older trees in small containers was compounded when the stock market crashed in 2008, causing home and commercial construction to plummet and the need for landscaping to plunge along with it.
While some nurseries junked their stock, others held on in hopes that the economy would turn around, Cox said.
Santa Monica comes with a unique pressure. The City Council accepted the Urban Forest Master Plan in November 2011, a document which spells out specific kinds of trees that can be planted on each street in the city.
Some of those, like the Canary Island date palm, are more rare than others, and can be difficult to find, leaving a contractor like West Coast Arborists and employees in the Public Landscape Division to choose between leaving a space blank or filling it with a sub par tree.
“Let‚Äôs pick species that are commonly available, where nurseries are growing them and have staff impact the trees,” Andy Trotter, an employee with West Coast Arborists, the company that plants trees for Santa Monica, told the Urban Forest Task Force in April.
The company will turn over a database of trees that have failed and how often they have been replaced, although a timeline for that release has not yet been worked out, city officials said.