Ornamental Grasses For Minnesota COLLEGE OF AGRICULTURAL, FOOD AND ENVIRONMENTAL SCIENCES M. Hockenberry Meyer, Assistant Professor D. B. White, Professor H. Pellett, Professor Department of Horticultural Science Ornamental Grasses Hardy in USDA Zone 4a. The following survived ten winters, 1987-1997, at the Minnesota Landscape Ornamental or landscape grasses have been Arboretum. used in gardens for centuries. In recent years Botanical Name* Common Name they have become popular in the United States. Acorus calamus sweet flag However, a lack of information on hardiness ‘Variegatus’ variegated sweet flag and performance in Minnesota has limited their use here. Alopecurus pratensis ‘Aureus’ yellow foxtail This fact sheet reports the results of a winter Arrhenatherum elatius ‘Variegatum’ bulbous oatgrass hardiness study in which more than 80 orna- curtipendula side oats grama mental grasses Calamagrostis x acutiflora ‘Karl Foerster’† feather reedgrass were grown (synonym Calamagrostis x acutiflora ‘Stricta’) successfully in Calamagrostis brachytricha† fall blooming reedgrass USDA Zone 4a where the an- Carex digitata finger sedge flacca blue sedge nual minimum flava† yellow sedge temperature ranged from Carex grayi Grays sedge Zone 4a montana† mountain sedge -20° to -30°F. muskingumensis† palm sedge The research nigra black flowering sedge was onducted Minnesota speciosa ‘Velebit Humilis’ velvet sedge Landscape umbrosa umbrosa sedge at the Minnesota Arboretum Landscape Deschampsia caespitosa† tufted hairgrass Arboretum. ‘Bronzeschleier’ bronze veil hairgrass Recommedations ‘Fairy’s Joke’ fairy’s joke hairgrass for culture and ‘Goldgehaenge’ gold pendant hairgrass ‘Scottland’ Scotland hairgrass maintenance along with special features of ornamental grasses are also provided. amethystina ‘Bronzeglanz’ bronzeluster fescue ‘Klose’ klose fescue Desirable Traits ‘Superba’ supurba fescue Ornamental grasses can provide an attractive Festuca cinerea ‘Blaufink’ blue finch fescue new look in gardens. Desirable traits include: ‘Blauglut’ blue ember fescue ‘Blausilber’ blue silver fescue  Very few insect or disease problems ‘Daeumling’ tom thumb fescue ‘Fruehlingsblau’ spring blue fescue  Low nutrient requirements ‘Harz’ harz blue fescue  ‘Meerblau’ ocean blue fescue No maintenance except spring cutback ‘Sea Urchin’ sea urchin blue fescue  ‘Solling’ solling blue fescue More than one season of interest; flower- ‘Superba’ supurba blue fescue ing in spring, summer, or fall, with beauty and color lasting into winter Festuca muelleri Muellers fescue Festuca tenuifolia fine-leaved fescue  Fast growing; large plants grow 5-8 feet tall by the second year Hakonechloa macra hakone grass †  Varied textures, from fine fescues to coarse Helictotrichon sempervirens blue oatgrass giant miscanthus Hystrix patula bottlebrush  Foliage colors of blue, yellow, bronze, red, Juncus effusus common rush and also variegated white and yellow brevis blue hairgrass  Movement with the wind providing Leymus arenarius blue lymegrass sound as well as interest and beauty (synonym Elymus arenarius) Culture and Maintenance Ornamental Grasses Hardy in USDA Zone 4a (continued) In Minnesota, ornamental grasses are best Botanical Name* Common Name planted in spring. Fall planting may be successful Leymus racemosus giant blue rye using container-grown plants, but winter protec- (synonym Elymus giganteous) tion may be necessary. Local nurseries and gar- Luzula sylvatica greater woodrush den centers often sell grasses and usually supply † large well-developed plants, but typically do not Miscanthus floridulus giant miscanthus offer the variety that is available from mail order Miscanthus oligostachyus† small Japanese silvergrass nurseries. Miscanthus sacchariflorus Chinese silvergrass Spacing is determined by the desired land- Miscanthus sinensis ‘Purpurascens’† red flame miscanthus scape effect. A rule of thumb is to space plants † equal to their mature height (thus plants 4 feet Miscanthus sinensis ‘Siberfedher’ silverfeather tall are spaced 4 feet apart), and the rule can be Molinia caerulea moorgrass adjusted according to the end result desired. ‘Heidebraut’ heather bride moorgrass ‘Moorhexe’ moorwitch moorgrass Grasses used as a hedge or screen are generally ssp. arundinacea tall moorgrass planted closer together. ‘Bergfreund’ mountain friend tall moorgrass Propagation is usually by division (digging the ‘Skyracer’ skyracer tall moorgrass ‘Staefa’ stafa tall moorgrass and cutting the crown and roots), especially ‘Transparent’ transparent tall moorgrass for named varieties or cultivars. Seed propagation, ‘Windspiel’† windplay tall moorgrass although successful, often results in flower and fo- Panicum virgatum switchgrass liage color variation and re-quires several years to ‘Haense Herms’† red switchgrass obtain mature plants. ‘Rehbraun’† red-brown switchgrass † Large, mature grasses may benefit from spring ‘Rotstrahlbusch’ red rays switchgrass ‘Squaw’‡ squaw switchgrass division, especially if the center of the plant is 'Strictum’ tall switchgrass dead. This can be a major job requiring a sharp ax ‘Warrior’‡ warrior switchgrass or spade and a strong back. Phalaris arundinacea ‘Picta’ ribbongrass Each year in early spring, about the first week Phalaris arundinacea luteo-picta yellow ribbongrass in April in Minnesota, cut ornamental grasses back to the ground to remove the previous year’s Phalaris arundinacea ‘Feesey's Form’† Feesey's form ribbongrass growth. When ornamental grasses are not cut Schizachyrium scoparium† § little bluestem back, spring growth is delayed and the plants (synonym Andropogon scoparius) look messy and half dead late into the growing Aldos; Little Camper; Blaze season. Manual trimming with a string or electric † blue moorgrass hedge trimmer works well for a few plants. Large Sesleria heufeliana† green moorgrass areas can be burned, if burning is permitted and closely supervised. Do not cut in the fall, because Sesleria nitida† grey moorgrass winter injury may result, and the winter beauty of Sorghastrum nutans† § Indian grass the plants will be lost. ‘Holt,’ ‘Osage,’ ‘Oto,’ ‘Rumsey’ Ornamental grasses rarely need fertilization or Spartina pectinata cordgrass irrigation after establishment, except in cases of ‘Aureo-Marginata’† variegated cordgrass extreme drought or very sandy soil. Most grasses Spodiopogon sibericus† spodiopogon prefer full sun. A few types of ornamental grasses Sporobolus heterolepsis† prairie dropseed have invasive rhizomes, but most form dense clumps or bunches. Stipa extremorientalis eastern feathergrass For detailed information and color photos of Themeda triandra ‘Japonica’ Japanese themeda ornamental grasses, order the 32-page bulletin, Or- *Plants are listed with names as received, except where synonyms apply. namental Grasses for Cold Climates, BU-6411, from †Attractive, easy to grow, especially good choice for Minnesota. University of Minnesota Extension Service Distri- ‡Planted in 1989. bution Center, 1420 Eckles Ave., St. Paul, MN §Planted in 1988. 55108-6069.

FS-6422-A Revised 1998 www.extension.umn.edu

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