WASHINGTON — Henry Mitchell liked azaleas (and many other plants). “With them,” he once wrote, “you can be as riotous, gaudy and vulgar as you please, or as delicate.”

Mitchell died in 1993, but his garden books flourish. Last week, more than 60 friends gathered at the National Arboretum to dedicate the Henry Mitchell Walk, a hillside path that takes the visitor through the arboretum’s azalea display gardens, now aglow in blooms.

More than 250 newly installed signs identify individual plants and also interpret the collection of azaleas. The shrubs are grouped by color but also by type; the signs are intended to give people a better understanding of differences in azalea form and size, and how they can be used.

Two other influential gardeners are already honored: B.Y. Morrison, who bred azaleas hardy to the Washington region; and Frederic P. Lee, who popularized them in a definitive book in the 1950s.

Coincidentally, the walk dedication coincides with the reissue of three of Mitchell’s books: “One Man’s Garden,” “The Essential Earthman” and “Henry Mitchell on Gardening.” “One Man’s Garden” contains newly published ink-and-wash drawings by Mitchell’s longtime illustrator, Susan Davis.