Hereford St. to Mass. Ave. Block of the Commonwealth Avenue Mall Receives Extreme Makeover

The Commonwealth Avenue Mall Committee (a joint committee of the Friends of the Public Garden and the Neighborhood Association of the Back Bay) is restoring a block of the Commonwealth Avenue Mall.

BOSTON/March 12, 2011. The Commonwealth Avenue Mall Committee [CAMC] (a joint committee of NABB and the Friends of the Public Garden) is launching a demonstration project on the Mall between Hereford St. and the Mass. Ave. underpass. With the encouragement and cooperation of the Boston Parks and Recreation Department, this 23,000 square foot area will be treated with a new landscape restoration technique called Air-Spading.

“The Friends of the Public Garden are delighted to be working with NABB to make a difference on this section of the Mall. This pilot restoration project will give us a better understanding of how the growing environment can be improved not just here but in all of the parks of our care,” said Elizabeth Vizza, Executive Director of the Friends.

In urban parks, soil compaction is the primary reason for trees not being healthy and dying and for the turf never developing. Treating this condition in an established landscape was formerly done with a series of trenches, which caused significant damage to tree roots, or by an aeration drum that only superficially addressed the problem. About 10 years ago a new instrument called an Air-Spade was developed. It essentially emits a stream of air under very high pressure, which disturbs and literally blows up the soil to a depth of 8 or more inches. This is the only technique that is effective and not damaging in an established landscape such as the Mall.

This block was chosen because it has many zelkova trees with girdling roots, because the turf is almost nonexistent, and because of the very degraded condition of the soil.

Starting soon after the April 18th Boston Marathon, the air-spading will begin. The root flares of the existing trees will be exposed and the killing, girdling roots will be cut and removed. The soil will be amended with a custom blend of organic materials and fertilizers. The whole area will be regraded and reseeded with a special blend of shade-tolerant grass seed and the trees will be mulched. This process will take about three weeks. The initial work will be a little noisy and a little dusty, but everything will be done to mitigate this by using dust shields.

Following this work, the two grass panels will be fenced off with a sturdy and not ugly wire fence for the remainder of the summer. CAMC knows that this will be an inconvenience to those accustomed to walking their dogs and sitting on the benches in this block, but it is only temporary. The central pathway will remain accessible.

This is the largest single area ever to be treated in this way in the state. Many other park agencies and advocacy groups are very interested in this project as it may be the answer to the problems of compaction in other parks. CAMC has been systematically thinning the tree canopy here in anticipation of this work. The contractor is Maltby and Company, an experienced Stoughton-based landscape firm which has had great success with this technique on a smaller scale.

The Committee members are asking for the public’s cooperation in protecting this area while it recovers and appreciates people’s patience for the inconvenience. In addition, the project still needs financial help. The Committee needs to raise $25,000 of matching funds. NABB members are always generous to the Mall, but here is a chance to sponsor a ground-breaking project. Pun intended! Please direct questions, concerns, comments, or words of encouragement to Margaret Pokorny at mpok384@verizon.net. Contributions can be made to the Commonwealth Avenue Mall Committee and mailed to the NABB office. They are tax deductible.