Someone's Been Beautifying Gowanus With Lots Of Flowers

The waters of the Gowanus Canal may still be foul, but a garland of brightly-colored flowers and some hand-drawn chalk patterns on the Carroll Street bridge certainly has made the polluted waterway a whole lot prettier, no?

And just one block away, a whole lot of cut-out paper flowers attached to a brick wall at the corner of Bond Street and Second Street in Gowanus add a very nice touch to a rather drab brick building.
Does anyone know who the artist is?