CULTURAL INFORMATION BOTANY OF GRASSES

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Elvin Griffin
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2 H G F I E A B C D

3 Ornamental grasses recently surged in popularity as a choice selection for gardens. Not only do they thrive in a variety of tough growing conditions, grasses provide multiple seasons of interest for the garden through their foliage, their flowers and often the dry stems withstanding winter hardships. Some ornamental grasses are evergreen in eastern Pennsylvania. Providing remarkable textural features for garden settings, grasses soften the visual effects of hardscapes and bold-textured plants. Movement is also an added feature of grasses in the garden as foliage and flowers flutter with the slightest breeze. Don t forget the play of light on ornamental grasses; backlit, the thin leaf blades and flowers shimmer. CULTURAL INFORMATION This section provides general cultural information for ornamental grasses as a whole. Information specific to individual selections is provided with each plant description. When grasses are the topic of interest, true grasses, sedges, and rushes are typically lumped together. Thousands of varieties of these plants can be found throughout most of the world and thrive in a range of temperatures from below zero to above 100 F. The majority grow naturally in open areas, exposed to sun. Sedges and rushes tend to prefer shade. Few grasses are found in dense shade. Grasses are known to thrive in soils low in fertility with water conditions less than ideal for typical garden plants. Some do grow best in moist well-drained soil while others are adapted to heavy, wet clay, and even rocky, dry, infertile areas. A few will even growing standing water. Grasses are generally pest and disease free though occasionally a problem will arise. These situations can be curtailed by providing good growing conditions minimizing stress on the plants. The most common diseases found in grasses are foliar rusts. A rust is identified by orange-brown discolorations found randomly along the leaf blade. For control methods, consult a reference specific to grass pests and diseases. BOTANY OF GRASSES All grasses have underground rhizomes, a type of stem, from which they grow. The nature of these rhizomes varies with the species of grass, creating either a clump-forming grass or plant that will either vigorously or slowly spread from the initial plant. Keep in mind that even a clump forming variety slowly spreads away from the central plant. The stems of grasses, known as culms, may extend along the length of the plant or remain low to the ground. The foliage is held to the culms by a leaf sheath, an extension of the leaf, which wraps around the stem, holding the leaves in place. The leaves of grasses, known as blades, tend to be flat and narrow. The visible veins on the foliage are parallel to the length of the blade. The flowers of grasses are often miniscule and not individually ornamental. Being wind pollinated, they do not have large, showy

4 petals, which would attract animal pollinators. Individual flowers are clustered together in an inflorescence. Within the grass families, the inflorescence ranges in color from reds through purples, greens yellows and browns. Shapes can be full or open, feathery in texture or stiff. PLANT DESCRIPTIONS Grasses listed below can be found throughout the Arboretum s gardens and collections. They are listed alphabetically by their scientific (Latin) names within each garden area featured. The name of the garden or landscape area is shown before the grass descriptions begin. The number listed with the garden area corresponds to the number on the provided map. All of the grasses grown at the Arboretum are not listed; this list includes only those we recommend for home gardens. A. Entrance Garden Calamagrostis brachytricha Korean feather reed grass A native of eastern Asia, this clump-former grows naturally in part shade along the edges of woodlands but will thrive in full sun and a range of soils. In early spring, medium green blades appear and reach their mature 4-foot arching form by mid-summer. Tall spikes of roseflushed, long, feathery, bottle-brush-like flowers fade to sterling with age and last through most of the winter. Use seasonally in containers, in the garden as a single specimen, or make a statement with a mass planting. Carex ciliatamarginata 'Treasure Island' Like 'Silver Sceptre', 'Treasure Island's narrow green blades feature a green center but with a dramatic white edge. Also a Japanese native, 'Treasure Island' reaches a height of 3 inches and forms a 15 inch clump in three years. Carex siderosticha 'Lemon Zest' 'Lemon Zest' receives its name the dramatic golden color it maintains even in partial shade. Often used as a container planting, it reaches a height of 9 inches. 'Lemon Zest' prefers fertile, well-drained soils and spreads by rhizomes. Hakonechloa macra 'All Gold' - Japanese Forest Grass 'All Gold' is a reflection of its name with its long golden swordshaped blades of grass. 'All Gold' gracefully forms clumps throughout your garden creating a gentle appearance as it spills golden blades into garden pathways. 'All Gold' reaches a height of 2 feet and prefers part shade. B. Terry Shane Teaching Garden Hakonechloa macra Hakone grass

5 Beautiful, arching stems of this native to the wet cliffs of Japan, form loose, cascading mounds 3 feet high. Rich green foliage highlights the garden during spring and summer before turning copper in the fall, then persists through early winter. Relatively insignificant flowers appear in late summer. Grow in the shade in very warm climates and in full sun in moist areas. Hakone grass has great potential as an accent, a groundcover, a container specimen, or use to cascade over a rock wall or pond. Albovariegata has rich green foliage accented by creamy-white variegation. More vigorous than other cultivars, it can spread up to 3 feet. Aureola, more common than the species, it has a thin band of green throughout the foliage surrounded by striking yellow variegation, varying in intensity depending on the climate. In cooler seasons, the foliage is blushed with pink. Aureola is not as vigorous as the species, reaching only 2 feet. C. Biostream Panicum virgatum switch grass Switch grass, a slowly-spreading, clump-forming grass, is native to tall grass prairies, open ground, and open woods in most of the U.S. and thrives in long, hot summers. Stems, which vary in color from deep blue-green to pale green, emerge in late spring and will grow 4- to 8 feet tall and vary in form from being stiffly upright to open and lax. Fall encourages stems to become golden yellow before they finally fade to beige. Flower stems become visible in July, providing many airy panicles of pink flowers which form cream-colored seed heads. Switch grass will generally remain standing through the winter. Use this drought tolerant plant as a single statement in the garden or as a mass planting. Heavy Metal, the blue switch grass, is a very upright selection, growing to 5 feet in flower. The foliage is deep glaucous blue. Schizachyrium scoparium little bluestem Native to American tallgrass prairies, little bluestem can grow in a broad range of soil conditions from average to very dry, but, like other prairie grasses, it will not grow well in very fertile soils stems will droop rather than stand erect. Delicately textured leaves stand upright, in tight clumps, 2 to 4 feet high and will last through much of the winter. The foliage color can be variable from bright green to blue with the most common plants having green foliage highlighted with purple. Miniscule flowers appear late summer but transform to silver, contrasting beautifully with the copper tones of the fall foliage. Use little bluestem in clusters and place where the autumn and winter sun will provide backlighting for greater enjoyment. D. Gold Medal Plants Garden Deschampsia caespitosa tufted hair grass

6 Slender, dark-green foliage arches from neat, 2-foot, evergreen, tufted clumps. It enjoys moist habitats from meadows to bogs and damp woodlands. Beginning in late June, billowing cloud-like flower heads, inevitably reaching 4 feet, emerge green and transform to gold, shimmering when touched by the wind and backlit by the sun. The flower stalks will last into the first parts of the winter though they are fragile and will be broken in snow. Deschampsia, native to temperate areas of Europe and Asia, is a cool climate grass, not faring well in the extreme heat and constant humidity of the southern U.S. E. Metasequoia Allée Carex morrowii var. temnolepis Silk Tassel Hosoba kan sedge Hair-like foliage spills from the center of the plant creating a silver tuft. Two-foot wide clumps of the 1/8-inch wide foliage look best along the edge of a garden path or atop a wall where the delicate texture can best be admired. A native woodland plant, Silk Tassel will grow best in light shade but can thrive in sun with moisture. Luzula sylvatica 'Variegata' - Greater Woodrush The slowly spreading rhizomes of the greater woodrush form a weedproof carpet. This shade loving plant makes a wonderful groundcover. When the flower stakes emerge in the spring the plant is 24 inches tall. After removing the flower stalks, 'Variegata' is 12 inches tall. 'Variegata' leaves are thin with a creamy-white edge. F. North Kolberg Hall Hakonechloa macra 'Beni Kaze' 'Beni Kaze' makes a dramatic addition to your fall garden. It creates the traditional Hakonechloa green arching grass mound during the growing season and then bursts into a striking red color for your fall viewing pleasure. This striking plant reaches a height of 3 feet. G. Science Center Sporobolus heterolepis - Prairie Dropseed This Missouri native is often found growing in glades, prairies, and on open ground. This clump-forming, warm seasoned grass has finetextured, hair-like, green blades. From Aug. to Oct., these arching foliage mounds produce pink to brown tinted, fragrant plumes. Prairie dropseed reaches a height of 15 inches and 36 inches when in bloom. The Scott Arboretum uses prairie dropseed to beautify the infiltration beds located in front of the Science Center. This grass was selected for its ability to withstand drought conditions as the infiltration beds are a porous planting mix. This porous mix allows natural filtration of rainwater addressing stormwater run-off concerns. H. Harry Wood Garden Eragrostis curvula - Weeping Love Grass

7 Reaching a height of 3 feet, Weeping Love Grass is often used to control erosion. The hair-like foliage develops arching, open lavender-gray panicles in late summer. The green leaves become yellow to bronze for winter interest. E. curvula does well in sun, thrives in sandy soils, and tolerates drought conditions. I. John W. Nason Garden Calamagrostis acutiflora Karl Foerster feather reed grass The upright clumps of the feather reed grass begin growing in early spring. By summer, the lustrous, deep green, strap-like foliage, arches 4 to 5 feet high. Early summer also brings the first feathery flower stems, which emerge rosy purple. As summer continues, they eventually reach 6 feet tall and by the end of summer, the flower stems become narrow, buff-colored spires. The stems and foliage will last through much of the winter. Feather reed grass thrives in full sun and moist soil but it is also drought tolerant. Use as a single specimen or in clusters to create wonderful accents in a perennial border. Carex plantaginea plantain-leafed sedge The plantain-leaf sedge, a native of eastern North America, will grow 10 inches tall. This clump-forming sedge has glossy green leaves which last throughout the winter. The small insignificant flowers appear in May. This sedge will grow best in partial shade and is best when used as a groundcover. Eragrostis spectabilis purple love grass Purple love grass is a wonderful, delicate addition to a garden in full sun with good drainage as it is native to the open, sandy soils of much of North America. It will also thrive in dry, poorly drained areas. Dull green foliage, which spreads horizontally from the center of the plant, is covered by a 2-foot high luxurious cloud of delicate purple flowers which look like soft pillows in the garden. The flowers fade to buff before the entire plant goes dormant for the winter. Place this grass along the edge of a path or in the front of a garden where it can be admired. Miscanthus sinensis Morning Light miscanthus The slopes of low mountains in Japan are often covered with miscanthus, a clump forming grass. Thin, 3/4-inch wide blades appear in mid-spring, and reach up to 6 feet by mid-summer. Morning Light, with a thin green band in the center of the blade surrounded by creamy yellow margins, turns tawny-brown in fall. Flowers begin to form in August on tall spikes from the center of the plant. The tassel-like flowers open maroon by October and fade to silvery-white with the onset of winter. The flowers will last through mid-winter and endure light snows. This great textured plant loves full sun and is drought tolerant. It will tolerate light shade but not grow as vigorously. Nassella tenuissima Mexican feather grass

8 Mexican feather grass is a delicate and beautiful clump-forming grass for any garden and is particularly striking in the front of a border where it can be most enjoyed. Stunning light-bronze blades shift in the slightest breeze and grow no higher than 2 feet at the end of the season. Soft golden-blonde flower spikes add a subtle textural contrast. Like most grasses, the feather grass grows best in full sun with well-drained soil. Panicum virgatum switch grass For full description of switch grass, look under Biostream heading. 'Hanse Herms', the red switch grass, grows to just over 4 feet tall. The leaves of this selection are green throughout the summer and turn burgundy beginning in August. 'Heavy Metal' grows to just over 5 feet tall. This narrowly upright form has dusky blue leaves. Sorghastrum nutans Sioux Blue blue Indian grass A staple grass from the North American tall grass prairies, Indian grass, which grows in tight clumps, stands upright when grown in full sun. As with many other prairie plants, it is drought tolerant and can withstand high temperatures and poorly drained soil. Sioux Blue is enhanced by upright, powder blue foliage, converting to dark yellow as fall progresses. Six-foot flowering stems stand above the foliage and display thin, airy, hazy-purple flower clusters which fade to buff as the season progresses. Both foliage and flower stems are strong enough to last through much of the winter. Spodiopogon sibiricus Siberian graybeard Siberian graybeard, native to eastern Asia, is a clump forming grass though the broad, matte green 4-foot tall foliage is held almost 45 from the central axis, creating an informal statement. Thin open panicles of flowers peak above the foliage by July and into August. As autumn arrives, the foliage develops into a deep burgundy-red generating a dramatic element for fall gardens. Spodiopogon grows well in full sun but prefers light shade. The overall form will be more relaxed and open with increasing shade. It is not drought or heat tolerant. Credits The cover illustration for this brochure was created by Barbara Seymour. This brochure was written by Allison Necaise in 2002; Modified in 2003 and 2006 by Becky Wehry, Member and Visitor Programs Coordinator. About the Scott Arboretum The Scott Arboretum is a public garden covering more than 300 acres of the Swarthmore College campus and displaying over 4,000 different kinds of plants. The Arboretum is a garden of ideas and suggestions, displaying some of the best trees, shrubs, perennials, and annuals for use in the Delaware Valley. Established in 1929 as a living memorial to Arthur Hoyt Scott, the Arboretum is open to the public year-round, free of charge, from dawn to dusk. Office hours

9 are Monday through Friday, 8:30 a.m. to noon and 1:00 p.m. to 4:30 p.m. Memberships to The Associates of Scott Arboretum are available. The Scott Associates aid efforts through financial and volunteer support. For more information, please call the Scott Offices at We welcome your questions, suggestions, and most of all, visits to the Arboretum. Visit us on our web site at The Scott Arboretum of Swarthmore College 500 College Avenue Swarthmore, PA

2015 Plant Catalog--- Kalmia to Perennials

2015 Plant Catalog--- Kalmia to Perennials Kalmia Culture. Best grown in cool, moist, rich, acidic, humusy, well-drained soils in part shade. Mulch to retain moisture and keep root zones cool. Carol Bright