Tree Pruning Moratorium Sought

The day that Sharyn Romano drove down Rossmore Avenue and saw a row of hacked, crooked trunks replacing the street’s leafy canopy of elms, something snapped.

“I was appalled. Outraged,” she said, clutching her abdomen as she revisited the Hancock Park street in memory. “Sickened to my stomach.”

Marshaling some of Los Angeles’ most prominent arborists, from state officials to the head of the city’s tree advisory panel, Romano has mounted a campaign for a moratorium on tree pruning in the city. The City Council moved cautiously to look into the complaints earlier this month. Street tree officials, meanwhile, are busily defending their record, and say the problem lies elsewhere.

Like nearly everything else in the urban environment, our view of trees is in flux--and fraught with contradiction and conflict.

In the last five years, new guidelines for pruning have been adopted by the International Society of Arboriculture. The guidelines, based on new findings about how trees respond to injuries, call for pruning that is much kinder to the natural structure of the tree. So much so that, today, “a really well-pruned tree, you don’t know it’s been pruned,” said Bruce Hagen, urban forester for the California Department of Forestry.

But kinder, gentler pruning looks like skimping to the untrained eye, leaving cities with the dismal choice of pleasing experts or pleasing constituents.

Small wonder that tree-cutting industries and bureaucracies have been sluggish in adapting, said Bill Kruidenier, executive director of the International Society of Arboriculture.

Toughest of all has been convincing the public. Many people are so used to such practices as “topping” trees--an idea that makes arborists wince--and hacking them down like winter roses that they demand outdated methods, Kruidenier said.

So the landscape continues to be dotted with hardwoods cut like Joshua trees, probably doomed to die young. Those initiated in the new wisdom grit their teeth and avert their eyes.

“It’s making us nuts,” said Romano, an arborist in training and director of the Hollywood Beautification Team. “You just want to scream.”

Los Angeles has about 680,000 street trees, mostly imported oddities from the East or the tropics, surviving uneasily in a strange, harsh land. They are at war with power lines, sidewalks and sewer pipes. Many are simply the wrong tree in the wrong place--and no amount of chopping will help these arboreal immigrants assimilate.

And because this urban forest was planted almost all at once, it’s all growing old at the same time.

But Chuck Hewitt, instructor of horticulture at Mt. San Antonio College in Walnut, said the greatest of all threats to urban trees is bad pruning. “There is a lot of hat-racking,” he said. “It’s just not right.”

The Los Angeles street tree division trims 90,000 trees a year. Prunings have been accelerated as the division’s budget has expanded, and more tree work is expected if the city launches a proposed sidewalk rebuilding program.

Critics worry over what they call poor practices--cutting off more than a third of a tree’s canopy, hacking branches in mid-span and topping, except when there’s no way to avoid it.

Cut trees in these ways and at first skinny branches spurt out, suggesting healthy regrowth. But this “stress growth,” as it’s called, only signals that the tree’s structure is permanently damaged, Hewitt said.

Badly pruned trees can take 15 years to die, arborists say; by the time they do, the error is often long forgotten. In the meantime, the experts add, the trees are more prone to disease and rot, more likely to fall or drop branches--the sort of thing our litigation-prone environment turns into liability. Paradoxically, they will also need more pruning, Hewitt said.

“I do not know for a fact that it is standard practice” in L.A. to prune improperly, said Linda Romero, urban forester with the state Forestry Department. “But given the number of these trees I have seen in Los Angeles, it appears to be.”

But Bob Kennedy, head of the street-tree division, guessed that in only 3% of cases does the city err in the way it prunes. His staff follows the standards, he said.

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He pointed the finger at other chain-saw-wielding contractors--those hired by the Department of Water and Power, the Los Angeles Unified School District, billboard companies and homeowner groups--as the real culprits behind the overzealous amputations.

“You’d be amazed. There’s these nonlicensed contractors out there,” Kennedy said. “Or citizens take it upon themselves to prune trees without a permit. . . . They should be looking at the way we trim trees as a model.”

As for the trees on Rossmore, Kennedy allowed that when he saw them, “I thought, ‘Wow, they hit them really hard.’ ” But he said an arborist later determined that the trees had rotting disease--forcing the contractor to cut more than usual. Other trees were then cut, for a “uniform look,” he said.

Changes have been made at the DWP, which trims 100,000 trees a year to clear power lines, said Tom Deal, superintendent of tree operations. This year the utility is requiring contractors to follow the new standards.

Kennedy and Deal said change is made more difficult by residents who have yet to embrace the new ways.

“We get a complaint that we cut too much, then we’ll get other complaints that we didn’t cut enough,” Deal said.

Said Kennedy: “We have to balance what the property owners want with the best arboriculture practice.”

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Taking Too Much Off the Top

Urban trees are pruned in order to remove dead branches and foliage for the health of the tree, and to make room for utilities such as power lines. Shown below is an example of how trees are affected by a bad pruning technique called topping, compared to good pruning. Topping, also called hat-racking, is used to reduce the height of a tree, but can damage and even kill healthy trees.

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Molding the tree to the right size as indicated in white

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Good Pruning

Year One: Size is reduced by cutting strong lateral limbs. This thins the tree, maintaining its natural form.

Year Three: Size is better controlled and tree develops more normally

Year Six: Foliage grows more slowly and is distributed more evenly.

Topping

Year One: Branches are cut down to stubs. Stubs are vulnerable to insects and disease.

Year Three: Stubby branches sprout abnormally fast. Sprouts are more weakly attached than a limb that develops more normally.

Year Six: Topped tree is as tall and bushy as it was to begin with.

* Source: International Society of Arboriculture; Tree City USA Bulletin