I had fun last year designing and assisting with the installation of a waterside buffer garden at Lake Hayward, East Haddam, CT. Now the garden is maturing and the photos below show what we saw on June 21, 2014: Yarrow and Penstemon (aka Beardstongue) were in full bloom. Both plants have a lot of ecological value. Penstemon is recognized by the Xerces Society as attracting large numbers of native bees. Yarrow is both attractive to native bees and attracts predatory or parasitoid insects that prey upon pest insects.
See the Lake Hayward garden web site.