Silphium is a tall, long-lived perennial in the sunflower family that is native to much of eastern North America and is a highly attractive plant for bees during the summer months. Found in various prairie and tall grass habitats, Silphium species produce large, yellow flowers from late June through August.

 

Native Regions

Eastern half of the United States and Canada

 

Availability

Silphium are long-lived perennials, native to eastern regions of the United States and Canada. Long tap roots, in some species extending 12 feet deep into the soil, make them hardy, generally drought-tolerant plants. Several species are commercially available.

 

Duration

Perennial

 

Bloom Time

Summer

 

Average Height

5 to 6 feet

 

Flower Color

Yellow

 

Exposure

Full sun

 

Water Requirements

Average to dry

 

Recommended Species

Silphium laciniatum (compass plant) is native to the eastern United States, with the exception of the Southeast seaboard. The rigid, coarse leaves orient themselves in a north to south direction to avoid the direct rays of the midday sun, thus leading to the plants' common name – compass plant. Scattered along the top half of the stout, sticky stem are 2-5 inch wide, yellow flowers which appear from July through September. The flowers attract many native bees, including bumble bees, as well as butterflies and birds. Compass plant, which is commercially available, has a high drought tolerance and can be grown in a variety of soils.

 

Silphium perfoliatum (cup plant) is found throughout the eastern United States, east of the Mississippi and eastern Canada. It produces the largest, most richly colored flowers of any Silphium species, and the small cup formed by the leaves holds water which attracts birds – hence the name, cup plant. The flowers are a favorite of native bees, and also attract butterflies and hummingbirds. The hollow stems of this plant provide nesting habitat for small carpenter bees and leafcutter bees. Cup plant has an irrepressible desire to reproduce, popping up everywhere and requiring minimal care, once established. Due to this facility for vigorous propagation, it is considered potentially invasive in some settings, and so has been banned in Connecticut.

 

Silphium integrifolium (whole leaf rosinweed) is a hardy perennial, native to prairies of the midwest United States. Somewhat smaller than cup plant and compass plant, rosinweed grows 2 to 6 feet, producing yellow composite flowers in July through September. As with other Silphium species, rosinweed attracts a variety of native bees.