Rick’s Native Plant of the Month | Panicum amarum

September 22, 2021

By Rick Bogusch

Bridge Gardens

Our native plant of the month is Panicum amarum, commonly known as bitter switchgrass, which can be found in coastal areas from Connecticut to Florida and right here on Long Island. Tolerating a wide range of soil and moisture conditions, including sandy, infertile loams, it is a great plant for naturalizing and for rain gardens. Under garden conditions, it will grow four to five feet tall, but on drier sites, three to four feet is the norm. Though it will grow in part shade and along woodland edges, bitter switchgrass does best in full sun. It’s a clump-former and will not spread from underground rhizomes, so it is a good choice for planting with native wildflowers like goldenrods and asters.


Bitter switchgrass, 'Dewey's Blue,' stands out when paired with goldenrod and a self-sown purple tall verbena.

Leaves are an attractive blue-green and flowers open flag-like on tall, sturdy, wind-proof stems in September. Seed heads ripen in early fall and persist into winter when the whole plant turns a warm, parchment brown. Cut to the ground from early winter through early spring to keep plants looking tidy.


Bitter Switchgrass, 'Dewey's Blue, near the shed

At Bridge Gardens, we have a variety of bitter switchgrass called ‘Dewey’s Blue.’ Leaves and stems are powder blue, hence the name, and it is one of the most ornamental and border-worthy grasses, native or non-native, a wonderful substitute for invasive Miscanthus. You can see ‘Dewey’s Blue’ in the bed surrounding the community garden’s maintenance shed in our Outer Garden.

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