Viewpoint: Precious urban oaks need local care

Two trees were fatally damaged by the construction of a driveway at 5333 Connecticut Ave. NW. (Brian Kapur/The Current/July 2017)

I was saddened to read The Current’s July 12 article about possible mortal damage to venerable red oaks caused by the large apartment development at 5333 Connecticut Ave. NW.

These kinds of outcomes are all too common in a city where construction unavoidably takes place under the tree canopy. Contrary to popular belief, most tree roots spread horizontally, to the “drip line” of the tree’s full canopy or farther. That means it is very difficult to avoid harming mature trees on a small construction site.

The D.C. government should do all it can to protect our mature tree canopy. Meanwhile, there are many opportunities for residents and business owners to enhance the “City of Trees,” as Washington, D.C., has been known for more than 100 years, according to Melanie Choukas-Bradley, author of the book of the same name.

The first way is often staring you in the face. Oaks, as we know, are prolific acorn producers. Any patch of dirt or lawn will provide all an oak acorn needs to take root and produce its first few leaves. Once you see more than a few, oak leaves are easy to recognize.

If an acorn has sprouted in the corner of your yard, and that area gets at least a half-day of full sun, you might consider “adopting” that free tree. Mulch around the seedling (not more than an inch deep) and water regularly, especially during hot dry spells in the summer. That’s all you have to do. Native to this area, the oak species are adapted already — giving them a little attention in the first years will almost guarantee survival and produce a thriving tree. Choukas-Bradley notes that our region is home to more than 20 species of native oak trees.

It is particularly urgent that we encourage new oak growth because it is a long-lived tree that provides extraordinary benefits to people and wildlife. The shade from an oak tree can keep your house from overheating in the summer, for example. A large oak soaks up large quantities of stormwater runoff, protecting Rock Creek and the Chesapeake Bay watershed. And scientists have documented that oaks, in the Mid-Atlantic region alone, harbor more than 500 beneficial species of insects, providing perfect food for birds and their young.

Yet there are many obstacles to the successful replacement of the current oak canopy. In our parks, deer have destroyed several generations of oaks by gobbling up the seedlings as fast as they sprout. Invasive non-native vines blanket many young trees and eventually kill them by depriving the tree of light.

In addition, the oak is rarely planted these days by home and commercial builders because it is a slow-growing specimen that doesn’t have a gaudy flower (though the autumn color should be appreciated). And when the oaks do sprout in neglected corners or on city median strips, they are cut down as “weeds.”

You can also buy a young oak sapling and plant it in a sunny part of your lawn. Keep in mind that the 5-foot tree you plant could take 50 or more years before it reaches its natural height. Meanwhile, enjoy that young oak — a species that has been venerated by many cultures for thousands of years.

Steve Dryden is founder and director of the Rock Creek Songbirds habitat restoration project in Rock Creek Park.