Silphium trifoliatum - WHORLED ROSINWEED

Showy and tall native perennial with typical whorls of three leaves and many yellow flowers.

Usually 5' tall x 1-2' wide, vase shaped clumps. But on nutrient rich soils 6-7' tall and smaller and more strictly narrow on leaner soils, usually only 4' tall.

Flowers from July till August/September.

Full sun, half shade, very adaptable to soil types and moisture - will grow virtually in any soil that is not waterlogged (sandy, rocky, shallower, loamy, clay). Average moisture (medium) to medium-dry.

Heat, humidity, drought and black walnut tolerant.

Deer and rabbit resistant, suitable for zones 5 to 8.

Native to eastern part of USA, see the USDA distribution map.

Attracts many native bees, a bit less butterflies and small songbirds. A bit similar species to Silphium integrifolium. Older scientific name is Silphium astericus var. trifoliatum.

Pot size : square 3.5" x 5" deep pot

Picture copyright : Sam Bahr, University of Maryland