Schizachyrium scoparium and cultivars
Little bluestem is a tough and dependable clumping deciduous grass. Native to a broad swath of North America, it was one of the dominant grasses of the vast tallgrass prairies.
In average to lean, well-drained soils, stems will remain upright. However, it can flop easily if conditions are too rich or moist. Cultivars have been selected for shorter plants, enhanced leaf colors, and stronger stems.
Summer through fall, the slender leaves and stems of little bluestem are an ever-changing kaleidoscope of gray-green, blue, pink, purple, copper, mahogany, red, and orange tones. Wispy silver-white seed heads sparkle in autumn sunlight and coppery brown leaves persist through winter.
It blends well with many perennials. That includes asters, sedums, coneflowers, and other grasses.
Native grasses play their part in the pollinator story too. Little bluestem is a larval host for a variety of butterflies and moths. Among these are the crossline skipper (Polites origenes), Dakota skipper (Hesperia dacotae), and Ottoe skipper (Hesperia ottoe).
Scoparium, little bluestem’s botanical epithet, means “like a broom,” an accurate description of its overall shape.
Little bluestem’s spikiness complements native and non-native perennials alike. An easy fit for mass plantings or meadows, it is just as brilliant in traditional borders, gravel gardens, and green roofs. Perfect partners are recent Perennial Plant of the Year winners. This includes such plants as lesser catmint (Calamintha nepeta nepeta), butterfly weed (Asclepias tuberosa), Hummel’s betony (Stachys ‘Hummelo’) and ‘Millenium’ allium (Allium ‘Millenium’).
Of course, with a name like “little bluestem,” you can’t help wonder if there isn’t a big bluestem … and there is, of course. Although the two are no longer considered to belong to the same genus, big bluestem (Andropogon gerardii) is likewise a grass of the tall prairie and also available as an ornamental grass, with several cultivars on the market. It tends to be a taller plant than little bluestem and grows under much the same conditions.
Hardiness: USDA Zones 3 to 9 (AgCan zones 4 to 9); AHS Heat Zones 7-1.
Light: Full sun
Size: 24–48 inches (60–120 cm) tall and 18–24 inches (45–60 cm) wide; cultivar sizes vary
Native Range: Eastern North America, from Alberta to Quebec south to Arizona and Florida
Soil: Dry to medium, well-drained soils. Adaptable to a range of conditions such as clay and poor soils. Does not like overly wet conditions.
Watering: Water well, keeping the soil relatively moist, as the plant settles in. Once established, grow it on the dry side. Plus, it has good drought resistance once established. Note too that it overwinters best when you keep it a bit dry.
Fertilizer: This plant isn’t a heavy feeder. Fertilize at a low to moderate rates. Excess nitrogen can lead to flopping.
Maintenance: Low-maintenance perennial grass. Cut back in late winter to early spring. Tolerant of heat and humidity.
Pests: Has few pest issues; scout for aphids and spider mites. Overwatering and too much nitrogen can increase the probability of root zone and foliar pathogens
Behavior: It’’s a clump-forming grass; clumps become denser and wider over time, but it doesn’t produce invasive offsets. It can, however, self-sow to a certain degree.
Propagation: The straight species and a few cultivars can be grown from seed. All can be grown from division and stem cuttings. Commercially, in vitro culture is popular as well. Do note that most cultivars are vegetatively propagated and patent-protected.
There are several cultivars. Most have either improved summer or fall coloration and/or a denser, more compact, more upright growth habit. All are hardy to USDA zone 3. Here are a few:
S. scoparium ‘Blue Heaven’: A tall but sturdy variety. It has purple-highlighted steel blue foliage in summer and a mix of purple, blue, red, pink, burgundy, and orange pigments in the fall. Glossy purple panicles turning into fluffy tan seed heads. 24–48inches × 18–24 inches (60–120 cm × 45–60 cm).
S. scoparium ‘Carousel’: Broad, basketlike base for a mounded effect. Blue-green leaves with pinkish midsummer highlights and a range of fall colors: copper, pink and mahogany. Sturdily upright, even in snow. 32 inches × 18 inches (80 cm × 45 cm).
S. scoparium ‘Chameleon’: Eye-catching variegated little blue stem, green and white in early summer, purplish red and pink in fall. Very compact 24 inches × 18–24 inches (60–120 cm × 45–60 cm).
S. scoparium ‘Jazz’: Very compact, variety that doesn’t flop under less than ideal conditions. Steel blue leaves blushing reddish bronze in fall. 24 inches × 18 inches (60 cm × 45 cm).
S. scoparium ‘Prairie Blues’: Seed selection of a tall, but sturdy clone. Blue-gray summer foliage, turning reddish in fall. Downy white seed heads. 36–60inches × 18–24 inches (90–150 cm × 45–60 cm).
S. scoparium ‘Standing Ovation’ (Illustrated at beginning of article): Very strong leaves and stems resist flopping, even under high winds and pounding rain. Blue-green summer leaves picking up greens, pinks and purples. Reddish to orange fall coloration. 36–48 inches × 20–26 inches (90–120 cm × 50–70 cm).
S. scoparium ‘The Blues’: The most widely available cultivar. Blue foliage with red stems, picking up shades of blue, purple and orange as fall approaches. Can be floppy in moist soil or partial shade or when overfertilized. 32–36inches × 24–26 inches (80–90 cm × 60–70 cm).
Article derived from the website of the Perennial Plant Association, a trade association composed of growers, retailers, landscape designers and contractors, educators, and others that are professionally involved in the herbaceous perennial industry.