Wyethia amplexicaulis

Common Names

Mule's Ears, Mule-Ears, Northern Mule's Ears, Smooth Dwarf Sunflower, Black Sunflower, Mule Ear Dock

Summary

Mule’s ears, a native perennial forb in the Asteraceae, occurs in western North America from Washington to Montana and south to Colorado and Nevada. It grows from a stout taproot to typically 30–80 cm tall, with large glossy basal leaves and smaller clasping stem leaves; 1–8 bright yellow, sunflower-like heads with 8–21 ray florets surround a larger central head, and stems carry a resinous, aromatic surface; blooms occur May–June and the plant forms dense, aggressive stands on heavy clay soils in mesic sagebrush–grassland, open woods, and meadows.

Cultivation favors full sun and free-draining, gritty yet moisture-retentive soils; drought intolerance is noted. Propagation is by seed; cool–moist stratification enhances germination; seeds are dry achenes; sow in autumn with 7–10 day germination and about 2 weeks establishment, transplanting to field in late fall or early spring. Hardiness is in USDA zones 4–8. Uses include erosion control and mine-spoil rehabilitation due to a deep, dense root system and dense wildlife cover; forage value is generally low to unpalatable, and the plant forms dense stands that can dominate certain habitats.

Lifecycle

Perennial

Height

10 inches-3.5 feet

Hardiness Zones

Zones 4-8

Sunlight Requirements

Ideally full sun.

Soil Type

Well-drained clay-loam, loam, or sandy loam soils, pH 6.0–7.5

Soil Drainage

Well-drained soils

Soil pH

6.0-7.5

Bloom Color

Yellow

Bloom Time

Spring to Summer

Foliage Color

Green

Fall Foliage Color

Green

Leaf Lifecycle

Deciduous

Growth Rate

Moderate

Seasons of Interest

Spring and Summer

Propagation Methods

Seeds, Division, Vegetative propagation via sprouts from underground rootstalks or the root crown after damage

Attracts Wildlife

Attracts bees, butterflies, other pollinators, and birds