Wilson’s flock, circa 1919.

These days, lawmakers are talking a lot about cutting budgets but not much about cutting carbon emissions. With spring around the corner, soon it will be time for cutting grass.

President Obama could address all three concerns by bringing sheep to the grounds of the White House and National Mall.

Unlike conventional groundskeepers, sheep don’t require salaries and expensive benefit packages. Unlike conventional lawnmowers, sheep don’t pollute nor rely on foreign oil.

Sheep are powered by the grass they eat and then convert the clippings into a natural fertilizer. Sheep are nature’s own lawn mowers.

Sheep have saved us before in times of national crisis. President Woodrow Wilson brought a flock to the White House grounds during World War I. Led by a famed tobacco-chewing ram named Old Ike, the sheep replaced expensive gardeners, freeing up men to fight and slashing groundskeeping costs. Although they occasionally munched on rare shrubbery and perennials, Wilson’s flock trimmed the grass better than any lawnmower.

But the sheep did more than keep the grass at bay. The auctioning of prized White House wool raised over $100,000 for the Red Cross. That’s equivalent to $1.5 million in today’s dollars—money that could be well spent restoring the decrepit National Mall. But even beyond the sale of shearings, the federal flock would be an economic boon for Washington. Just think of the tourist kitsch.

Above all, returning sheep to the nation’s capital would encourage sustainable agriculture. Urban farming is an important component of making cities more ecologically sound, and turning Washington’s greatest open spaces into pastures would promote similar innovations across the country.

The Mall has been a symbol of our agrarian roots since the city’s founding. Its earliest incarnation was a pasture called the Commons. Even in its current form, the National Mall was meant to embody the American rural ideal: plans for its redesign in 1902 featured a watercolor of a shepherd and his flock ambling across the lawn toward the Washington Monument.

During the Wilson administration, the White House sheep came to symbolize national sacrifice for the war effort. Today, a new flock in Washington could come to symbolize a sustainable American future—both fiscally and environmentally.