A Second Life for a Tree

In the summer of 2013 a specimen lacebark pine (Pinus bungeana) at the National Museum of Natural History had been in decline for several months. An investigation by Greg Huse, Smithsonian Gardens arborist, found very large girdling roots growing just below the soil surface. In his report Lacebark Pine # 122 Evaluation at NMNH he determined there was little to no chance that the tree could be rehabilitated. Within two months of issuing the report the tree turned completely brown and it was clear that it need to be removed.

Or did it? Could the once stately pine on the corner of Madison Drive and 9th Street that formed the border between the Butterfly Habitat Garden and the newly established Urban Bird Habitat find a second life?

As a mature specimen of this slow growing pine the tree exhibited extraordinary exfoliating bark in a patchwork of white, olive, light purple and silver. The multi-stemmed trunk was a striking structural element in the landscape that would be a significant loss. Luckily, there was a way to save this feature and in doing so support wildlife enhancing the value and educational lesson of the space. The tree was the perfect candidate to become a snag.

By turning the soon to be rotting trunk and branches into a snag it gains a new purpose in the Urban Bird Habitat serving as a space for nests, nurseries, storage, foraging, roosting and perching for birds, small mammals, and other wildlife in the city.

Here is how we did it:

By September the tree had turn completely brown. Alas, it was dead and we sat early in the morning waiting for a professional tree crew arrive.

To create our snag we removed the top third of the tree and half the remaining side-branches. This method facilitates the inside-out decay process best for attracting cavity-nesting birds.

The jagged top and broken side branches give a more natural look to the snag. Furthermore, they speed up decay and provide hunting perches for hawks, eagles, and owls. (Note: this is the only instance when this is desirable pruning – don’t be surprised when your tree care professional gives you a strange look and makes you repeat your request several times to make sure that he or she is hearing you correctly).

The tree crew puts the finishing touches on their masterpiece which quickly became an attention grabbing feature at Smithsonian Gardens.

The before and after images of the tree show how we were able to maintain the great bark and interesting structure of the tree as a structural feature in the garden. (Perhaps our snag is some competition for Graft, the 45 ft. stainless steel tree installed by Roxy Paine in the neighboring National Gallery of Art Sculpture Garden in 2009)

The garden is a dynamic landscape and one must be prepared to deal with the changes that nature brings.  Through creative thinking the Smithsonian Gardens’ staff discovered a great opportunity to turn what could have been a significant loss to gardens into a valuable resource.  Today many museum visitors stop to look at this unique tree along the National Mall.  Most seems puzzled by its presence but their questions are answered by the Snag interpretive panel.

So what do you think?  Does your garden have a spot for a snag?  Please share your thoughts in the comments below.

-James Gagliardi, Smithsonian Gardens Horticulturist

Further Reading:
Living with Wildlife: Snags – The Wildlife Tree from the Washington Department of Fish and Wildlife.