Panicum virgatum
Switchgrass
Mature Size, Growth, Longevity
The foliage is mounded, but the flowers are upright. Gets 3-8' tall, with an upright-open, clumping habit, although some spread does occur through rhizomes. Winter habit is upright. Fast growth rate. Like most North American prairie grasses, this is a long-lived grass.
Native Range
Kentucky Native — Native to prairies and open grounds, open woods and marshes from eastern Canada through most of the United States, except California & the Pacific northwest. .
Flower and Fruit Details
The July-September, pink or dark red to purple-tinted flowers are borne in profusely in 6-24" long, fine-textured, dainty panicles, with 1/4" long spikelets. Color is most intense as flowers are just opening. It changes to beige as the flowers mature.
Leaf and Bark Features
Deciduous: Since this is a warm-season grass, new foliage emerges late in the spring. Summer foliage color ranges from medium green to deep green, to powdery-blue, changing to bronze at maturity. Fall foliage color is golden-yellow or bronze to burgundy, fading to beige.
Culture and Care
Adapts well to a wide range of soil conditions, including clay. Needs full sun to light shade. Tolerates moist, wet or dry sites. Tolerant of high winds and seaside conditions or de-icing salt in the soil. Can withstand soggy soils or occasional flooding. Tall plants may require staking. Zone 5(4)-9. Cut plants to the ground in March. No serious diseases or insect pests.
Strengths, Weaknesses, Other Facts
Good wildlife value. 4-season interest: Spring, summer, fall & winter. This is a warm-season perennial grass, a North American prairie grass.
Suggested Uses
Often used for background plantings, screening, specimen plant, fresh & dried cut flowers, and in sweeps or mass plantings along canals, waterways, pools, and highways. Also good in large containers.
Taxa and Plants of this Species at BCA
The following taxa are (or were) represented in the collections at Boone County Arboretum. Additional taxa may be available in the trade that are not included here.
Panicum virgatum 'Dallas Blues' // Dallas Blues Switchgrass
Grass. Grows to 4' tall. Flowers later than most of the other cultivars, usually in mid to late September. Distinct broad, steel-blue to gray-green foliage and dramatic purplish flower panicles. Leaves are 0.75" to 1.5" wide, powder blue. Foliage changes from lavender-purple to deep purple-red to tawny in late fall. Grows in almost any soil, in full sun to light shade. Higher than average drought tolerance, yet also withstands soggy soil. Propagate by division in spring. Zone 5(4)-9. Sturdy stems and inflorescences stand up well into winter, providing important cover for birds.
Bed 204 - Bed 208 - Bed 212 - Bed 240 - Bed 241Panicum virgatum 'Heavy Metal' // Heavy Metal Switchgrass
Grass. Grows like a 1-2' wide column, 3-5' tall; clumping form. Flowers have strong pink tones in the summer. Leaves are strongly glaucous-blue/metallic-blue, stiff and strictly upright, turning bright yellow in fall, then tan in winter. Even when winter-dried stems collect snow & flop, they almost always return perfectly upright as the snow melts away. Plant in full sun to light shade. Likes moist to wet sites. Tolerates drought. Good in rain gardens. Good cut or dried flower. Prone to foliar rust disease in hot, moist summers. Stems rarely lean or flop even in heavy rains. Even maintains its upright habit in the winter. Flowers are effective July-February. Provides food and shelter for songbirds. Introduced by Kurt Bluemel.
Bed 165 - Bed 172Panicum virgatum 'Northwind' // Northwind Switchgrass
Grass. Grows into a compact, narrow, erect, 4-6' tall and 2-3' wide clump. Blooms effective July-February. Flowers are yellow. Good in rain gardens. Leaves are olive-green to bluish-green, changing to bright yellow, then beige in the fall. Introduced by Northwind Perennial Farm. Good as an accent plant, or in groups or mass plantings, in a screen, wild garden, native plant garden, naturalized plantings, water gardens, rock gardens, bogs, near ponds, or in meadows and prairies. Also good for erosion control. Bird-friendly, providing food and cover.
Bed 204Panicum virgatum 'Rotstrahlbusch' // Red Switchgrass
Grass. Grows 3-5' tall and 2-3' wide, in an upright, vertical clump. The 3-4' silver-green leaves begin turning red in mid-summer, changing to bright red. In the fall, leaves become an outstanding burgundy-red, and finally change to tannish-beige for the winter. Plant in full sun. The pink-tinged flowers start blooming Jul/Aug; effective through February. Also known as 'Red Rays'. Prefers medium to wet moisture conditions, but also tolerates drought. Good rain garden plant. Also good for screening & massing. Suitable for Japanese-style gardens, native plant gardens, or meadows and prairies. Good in the perennial border. Roots hold the soil & help prevent erosion on slopes. Tolerates air pollution & juglone in soil from nearby walnut trees. Divide in spring.
Bed 184Panicum virgatum 'Shenandoah' // Shenandoah Red Switchgrass
Grass. Compact, narrow, erect habit. Grows 3-4' tall (in flower) and wide. Lowest and slowest growing of the switchgrass cultivars. Blue-green leaves in spring/early summer, taking on dark red/wine-colored tones by late June, then fully colored by September. Fall color is an unmatched dark burgundy. Fine-textured, reddish-pink flower panicles (held above the foliage) start in July and remain showy through February. Plant in full sun. Good rain garden plant, or in bog gardens and along ponds. Also good for slopes, screening, accent & massing. Suitable for native plant gardens, or meadows and prairies. Good in the perennial border. Pollution-tolerant.
Bed 172