Polly Hill Arboretum Again Achieves Highest Accreditation

Posted December 15th, 2017

This past February we received wonderful news: PHA had again achieved a level IV rating, the highest available, from the Arbnet Arboretum Accreditation Program in recognition of our commitment to the health and diversity of our trees. Level IV has been achieved by only 10 percent of botanic gardens and arboreta participating in Arbnet’s program designed to “establish and share a widely recognized set of industry standards for the purposes of unifying the arboretum community.”

Arbnet was established in 2011 by the Morton Arboretum of Lisle, Illinois, to support the work of arboreta to save and plant trees. The accreditation program establishes criteria for collections management with an emphasis on woody plants. The review is carried out by a diverse group of panelists from U.S. and international arboreta. At this time Arbnet has accredited 175 arboreta in 12 countries.

What makes a level IV arboretum? You must have a master plan that guides your collection development and outlines opportunities for expansion. Another critical planning document is a collections policy. Our guiding philosophy is to determine through experimentation the best plants to cultivate on Martha’s Vineyard; recognizing both our space limitations and local cultural conditions, we target well-adapted plants. Our collections policy informs plant acquisition and removals.

The level IV accreditation also recognizes our well-qualified staff and our commitment to managing our plant collection for the purpose of conservation, in addition to supporting the Global Trees Campaign, the only international program dedicated to saving the world’s threatened tree species. Who would have imagined when Polly Hill first started planting trees from seed in 1958 that 50 years later nearly 20 percent of tree species worldwide would be threatened with extinction? PHA is dedicated to protecting these vulnerable trees.

We plant and study trees, but we want our work to have deeper impact. We do this through research, education, and community outreach, including growing trees from seed and sharing our results. The Arbnet website states: “Level IV arboreta are world-renowned tree-focused institutions.” There are only 20 other institutions to achieve this level of merit! PHA staff and board are proud of this accomplishment.