He planted the seeds on the Upper East Side, but they also made their way to Queens. Today in that borough’s Kissena Park, within a 14-acre plot known as Historic Grove, a stand of katsura trees ...

Native to Japan and cultivated in gardens and arboretums all across the US since the mid-1800s, katsura leaves release a special compound called maltol that gives the air a cotton candy-like aroma.

An aging katsura tree planted in 1878 at the Arnold Arboretum in Jamaica Plain. (Alexandra Koktsidis/WBUR) A sweet, sugary scent tickles your nose, then disappears.

Q: We have a beautiful 20-foot katsura tree that has about a 4-inch-diameter trunk. We had it planted by a local nursery about two years ago, and it has done beautifully until late summer.