Like most gardeners, I was delighted when Michelle Obama announced the planting of an organic vegetable garden on the White House grounds. Converting a part of a water-wasting, chemical-using lawn to a kitchen garden that will help feed the family while not using pesticides and fertilizers is an extremely positive development in the land usage happening at this famous residence. But as a native plant nerd I would be remiss if I didn't advocate for the addition of native landscaping to the White House grounds. This would demonstrate to the public at large that while a vegetable garden feeds people, a restored native landscape nourishes the entire ecosystem, from the water resources to the soil to the wildlife.
Green the Grounds, a national media campaign, is asking how the White House and other First Residences can improve their land usage practices. Restoring the landscapes native to a residence's location would be one of the greenest options available. What I would truly like to see at the White House would be to convert the sun-filled front and south lawns to a meadow or prairie instead of the acres of turf grass currently there. A rain garden or wetland restoration would be a wonderful use of some particularly swampy microclimate on the grounds. (There must be a part of the grounds that fits that description. We are talking about a location on the cusp of the Atlantic Coastal Plain that's also near a large river; you can't tell me there isn't a marshy spot there somewhere!)
These landscapes would conserve water because the plants' massive roots can store large amounts of it, usually negating the need for irrigation. And when downpours come, that same web of roots and above-ground foliage will hold the soil in place and prevent erosion. Fertilizer would be counterproductive because native grasses and forbs become floppy with chemical additions. A few legumes would fix nitrogen in the soil, replacing a key nutrient that's been sucked up by all that turf, and I bet Sasha and Malia would love to see butterflies all over their yard.
But the best maintenance for a large-scale prairie is to burn it, and I'm pretty sure this would present a security issue. Even though controlled burns are carried out safely every year across the country, I can understand why many government officials, citizens, and even the first family themselves would object to a large conflagration surrounding one of the most important and valuable buildings in the world.
So I advocate that the White House grounds start small. Remove patches of turf and plant beds of prairie plants. Do likewise in the borders along the building in appropriate locations. Burning small native plantings isn't necessary; if things really need to be cut back, running over them with a simple push mower can replicate the effect of fire by reducing the plants to ground level.
Use Virginia switchgrass (Panicum virgatum) and Virginia wild rye (Elymus virginicus) as the matrix for the forbs; try broom sedge (Andropogon virginicus) in the drier spots. Grow these grasses with flowering forbs such as false indigo (Baptisia australis, a nitrogen-fixing legume), butterfly weed (Asclepias tuberosa), and heath aster (A. ericoides). For shady areas, replace turf with Pennsylvania sedge (Carex pensylvanica), and don't overlook spring wildflowers that look beautiful in those places, like Virginia bluebells (Mertensia virginica) and Dutchman's breeches (Dicentra cucullaria).
The grounds crew should find that soggy spot and plant a rain garden or wetland; those areas wouldn't burn anyway. Cardinal flower (Lobelia cardinalis) and great blue lobelia (L. siphilitica) are both appropriate for this region and they're fantastic for absorbing excess water, as is Canada rush (Juncus canadensis) and blue flag iris (I. versicolor). Throw in some New England asters (A. novae-angliae) to give a regional shout-out. Do you notice how these plants have American place names? Not only is it for a sensible reason (they evolved here), but it would add a personalized touch to the White House gardens.
These steps would improve the soil and provide food for wildlife, but perhaps most importantly they would conserve water in multiple ways, both by not needing irrigation and by preventing storm runoff from that massive lawn from reaching the Potomac River and Chesapeake Bay. Just yesterday NPR featured Hedrick Smith, who described how six-legged frogs and other monstrosities were being discovered in the Bay thanks to runoff carrying fertilizer, pesticides, and myriad other forms of pollution. The entire watershed and other bays along the Delmarva Peninsula are important and fragile ecosystems, as are the water resources across this country. By setting a good example of land-use and water-use practices, the White House could help encourage wiser use of those resources throughout the United States.
Last but certainly not least, native landscaping would show the nation and the world that ecosystems evolved in the ways they did because everything worked together. Plants, animals, fungi, every type of organism has its place in the environment where it grew and adapted. By growing the plants that are right for the land, the land will respond by supporting communities of healthy organisms. And if we're trying to encourage renewal and improvement of our country, I can't think of a better way than through the very landscapes we live in every day.