Trees tops in Boston

Most neighborhoods have iconic trees. The Back Bay has its magnolias. Beacon Hill blossoms with Callery pear trees in late April. The North End’s favorite trees are the lindens and locusts along the Prado, slated this spring for pruning. Charlestown has variety, with especially good gingkos.

Downtown residents get pretty agitated about trees. When city workers show up to cut down an ailing tree, neighbors appear on the sidewalk to challenge them. When a tree blows down in a hurricane in the Public Garden, garden lovers visit as if they are at a wake.

Recently a horde of opponents showed up at a Parks Department hearing. A Myrtle Street homeowner sought permission to chop down a mature linden tree behind his garden on Revere Street so he could cut into the curb and create a parking space for his car. No way, said neighbors. No way, said the Parks Department.

Mass General recently chopped down a special tree planted about five years ago. Bravely, because it’s hard to transplant big trees, MGH chose a tall Metasequoia glyptostroboites or dawn redwood tree for a small garden between the Yawkey building and the Liberty Hotel at Charles Circle. “Despite significant investment, it never actually thrived,” said Dr. Jean R. Elrick, MGH’s senior vice president for administration. An arborist said part of it was dead and in danger of falling. It had to go.

Dawn redwoods have a romantic history. Thought to be extinct, they were discovered in China during World War II. In the late 1940s this deciduous conifer’s cones were brought to the Arnold Arboretum, which grew saplings and distributed them throughout the world. The Public Garden has four of them, and one is now the park’s tallest tree. I hope MGH tries again with a Metasequoia, this time with a smaller specimen, which might have a better chance of survival.

Dawn redwoods grow relatively quickly and tolerate urban conditions well in northern cities.

And tough conditions are what trees have to endure on city streets. So tough, that city officials follow principles, said Greg Mosman, the city’s arborist.

For one thing, forget about those Beacon Hill blossoms. The pear trees break too easily. London plane trees, aka sycamores, are frowned on because of their susceptibility to fungus. Norway maples are no longer favored because they spread into vacant lots too easily, and they also rot. Those trees will be removed when they are compromised, and they won’t be replanted.

Gingkos, locusts and lindens are the best for our streets, said Mosman, but cherries, serviceberry (shadblow) and certain varieties of crabapples can be planted if a neighborhood needs some flowering types. Some people love the look of uniform trees forming an allée along a street, but that’s folly if that variety becomes susceptible to a bug. “We try to preach diversity,” said Mosman.

Planting trees is high on the city’s agenda for reducing temperatures, improving air quality and providing beauty. In 2007 the city announced that it wanted to increase the “tree canopy” from 29 percent to 35 percent by 2020, which meant that 100,000 trees needed to be planted, said Mathew Cahill, coordinator at the Boston Urban Forest Program, which administers the program for the city and is part of the Boston Natural Areas Network. The program gives grants to non-profit groups to plant trees around schoolyards, libraries, churches, and housing developments.

Neighborhoods vary widely in the amount of trees they contain with Boston central, which includes the North End and the Waterfront, having only 8 percent canopy. Charlestown has a canopy of 12 percent and the Back Bay and Beacon Hill together have 23 percent.

Beautify Boston is a city grant program instituted last fall that often involves trees. This year the Garden Club of the Back Bay will use its grant money to prune 67 linden trees between Berkeley Street and Massachusetts Avenue, some of which were planted in 1910. The Beacon Hill Civic Association will use another grant to plant and protect the tree pits along Charles Street.

The Parks Department plants trees if residents ask for them, said Jacquelyn Goddard, spokesperson for that agency. A request form is available on the Parks Department website. While residents are not required to take care of the tree, she said, the tree has a greater chance of survival if you water it. Fill the “gator bag” that comes with every new sidewalk tree with water once or twice a week.