WASHINGTON - In the District of Columbia, closet smokers are becoming closet growers. And basement growers. And attic growers. And on a recent Saturday, several hundred of them showed up at a specialty store in search of something to grow.It was a free "clone share" at Good Hope Hydroponics in Washington, and the line threading around the block waiting for the ready-to-root plantings showed how many people are cultivating their own marijuana in the nation's capital.