Ornamental Grasses: Beautiful and Easy Companions
(Editor's Note: This article was originally published on June 22, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
At least 100 varieties of ornamental grasses grow throughout the world: some small, some huge, some sprawling, some neatly mounded, some evergreen, and some seasonal. The one thing these plants have in common is that they are beautiful and, once established, very easy to maintain. Other positive aspects of grasses include:
- low maintenance
- texture, movement, contrast in a garden setting
- seeds for birds and other wildlife
- mostly pest- and disease-free
- hardiness and longevity
The North Carolina State University provided the following excellent list for reference when deciding on variety for your own property.
Adagio miscanthus, Miscanthus sinensis 'Adagio'
Alkali dropseed, Sporobolus airoides
Autumn moor grass, Sesleria autumnalis
Big bluestem; Turkey foot, Andropogon gerardii
Blonde sedge; Frosted curls sedge, Carex albula 'Frosted Curls'
Blue fescue, Festuca glauca (Festuca ovina var. glauca)
Blue lyme grass, Elymus arenarius (syn. Leymus arenarius)
Blue oats grass, Helictotrichon sempervirens (syn. Avena sempervirens)
Blue-green moor grass, Sesleria heufleriana
Broad-leaf whitetop sedge; Star sedge, Rhynchospora latifolia
Broad-leaved cotton grass, Eriophorum latifolium
Broomsedge; Beard grass; Broomstraw, Andropogon virginicus
Bush beard grass, Andropogon glomeratus (Andropogon virginus var. abbreviatus)
Cabert miscanthus, Miscanthus sinensis var. condensatus 'Cabaret'
Compact white-striped bamboo, Pleioblastus variegatus
Compact zebra grass, Miscanthus sinensis 'Hinjo' (Little Mickey)
Prairie cord grass, Spartina pectinata
Cosmopolitan, Miscanthus sinensis var. condensatus 'Cosmopolitan'
Creeping broad leafed sedge, Carex siderosticha
Dwarf miscanthus, Miscanthus sinensis 'Yaku Jima'
Evergold striped weeping sedge; Oshima kan suge, Carex oshimensis 'Evergold'
Feather reed grass, Calamagrostis x acutiflora
Flame grass, Miscanthus 'Purpurascens'
Fountain grass, Pennisetum alopecuroides
Giant blue wild rye, Elymus racemosa (syn. Leymus racemosus)
Giant miscanthus, Miscanthus floridulus
Giant reed, Arundo donax
Glaucous sedge; Carnation grass, Carex firma (syn. Carex glauca)
Gold feather, Miscanthus sinensis 'Goldfeder'
Gold fountains; Kaga brocade sedge, Carex dolichostachya 'Kaga Nishiki'
Golden hakonechloa, Hakonechloa macra 'Aureola'
Goliath, Miscanthus sinensis 'Goliath'
Graziella miscanthus, Miscanthus sinensis 'Graziella'
Gulf muhly; Pink hair grass; Pink muhly; Mule grass, Muhlenbergia capillaris
Hairy melic grass, Melica ciliata
Hakone grass, Hakonechloa macra
Hamelin dwarf fountain grass, Pennisetum alopecuroides 'Hameln'
Hare's-tail grass, Lagurus ovatus
Heavy Metal blue switch grass, Panicum virgatum 'Heavy Metal'
Hime kan suga, Carex conica 'Hime Kansugi'
Hosoba kan suge, Carex morrowii var. temnolepsis (Carex temnolepis)
Ice Dance carex, Carex morrowii 'Ice Dance'
Indian grass, Sorghastrum nutans
Japanese blood grass, Imperata cylindrica var. koenigii
Japanese sweet flag, Acorus gramineus
Job's tears, Coix lacryma-jobi
Kanuro-zasa; Compact golden-striped bamboo, Pleioblastus auricoma
Karl Foerster feather reed grass, Calamagrostis x acutiflora 'Karl Foerster'
Khus Khus, Vetiveria zizanioides
Korean feather reed grass, Calamagrostis brachytricha (Calamagrostis arundinacea var. brachytricha)
Large blue hair grass, Koeleria glauca
Lemon grass, Cymbopogon citratus
Lindheimer's muhly, Muhlenbergia lindherimeri
Little bluestem, Schizachyrium scoparium
Maiden grass, Miscanthus sinensis 'Gracillimus'
Malepartus miscanthus, Miscanthus sinensis 'Malepartus'
Marrow's sedge, Japanese sedge, Carex morrowii
Mexican feather grass, Nassella tenuissima
Sarbonde Miscanthus, Miscanthus sinensis 'Sarbonde'
Morning Light miscanthus, Miscanthus sinensis 'Morning Light'
Moudry, Pennisetum alopecuroides 'Moudry'
Mvenra grass; Ravenna grass; Hardy pampas grass, Erianthus ravennae
Nagasa bamboo, Sasa veitchii
Needle grass; Esparto grass; Mexican feather grass, Stipa tenacissima
New Zeland flax, Phormium tenax
Oriental fountain grass, Pennisetum orientale
Palm sedge, Carex muskingumensis
Pampas grass, Cortaderia selloana
Porcupine grass, Miscanthus sinensis 'Strictus'
Prairie droopseed, Sporobolus heterolepis
Purple fountain grass; Dwarf red fountain grass, Pennisetum setaceum (syn. P. macrostachynum)
Purple love grass; Tumble grass, Eragrostis spectablis
Purple moor grass, Molinia caerulea
Ravenna grass, Saccharum ravennae
Red silver grass, Miscanthus sinensis 'Rotsilber'
Ribbon grass; Gardener's garters; Reed canary grass, Phalaris arundinacea
Running bamboo; Golden bamboo, Arundinaria variegata (syn. Pleioblastriatus variegata)
Silver feather, Miscanthus sinensis 'Silberfeder'
Spodiopogon; Siberian graybeard; Frost grass, Spodiopogon sibiricus
Striped corn; Variegated corn, Zea mays
Sweet vernal grass, Anthoxanthum odoratum
Switch grass, Panicum virgatum
Taiwanese miscanthus, Miscanthus transmorrisonensis
Tall purple moor grass, Molina caerulea subsp. arundinacea
Tall switch grass, Panicum virgatum 'Cloud Nine'
Tenjiku suge, Carex phyllocephala
Tuber oat grass; Bulbous oat grass, Arrhenatherum elatius subsp. bulbosum
Tufted fescue, Festuca amethystina
Tufted grass; Tufted sedge, Carex elata (Carex stricta)
Tufted hair grass; Tussock grass, Deschampsia caespitosa (syn. Aira caespitosa)
Variegated manna grass, Glyceria maxima 'Variegata'
Variegated miscanthus, Miscanthus sinensis 'Variegatus'
Variegated sweet flag, Acorus calamus 'Variegatus'
Weeping love grass, Eragrostis curvula
Wild oats; Northern sea oats, Chasmanthium latifolium
Zebra grass, Miscanthus sinensis 'Zebrinus'
Before choosing a grass for your landscape, determine whether you want a cool season or warm season grass. Cool season grasses begin growth early in the spring and often remain semi-evergreen over the winter. During a drought, they will go dormant if not watered; this is not fatal, but the resulting brown foliage is not attractive. Most of these grasses are clumping, which means they will need to be divided as the years pass. Some popular cool season grasses are:
- Fescues such as tufted (Festuca amethystina) or blue (Festuca glauca)
- Blue Oat Grass (Helictotrichon)
- Tufted Hair Grass (Deschampsia)
- Autumn Moor Grass (Sesleria)
Warm season grasses do not begin growth until soil and air temperature have stabilized. These grasses do not remain green during winter, but do provide beautiful contrast and texture to a garden with their dried leaves, stalks, and plumes (which are also a source of food for over-wintering birds). Most of these grasses are also clumping and will need to be divided to keep them healthy, but not as often as cool season varieties. Additionally, in spring before new growth begins, the old stalks must be cut back to about 4 to 6 inches. Popular warm season grasses include:
- Switch Grass (Panicum)
- Hardy Pampas Grass (Erianthus)
- Perennial Fountain Grass (Pennisetum)
- Northern Sea Oats (Chasmanthium)
- Japanese Silver Grass (Miscanthus)
Another consideration before choosing a grass is to determine the final location as it relates to your other garden beds. Some grasses form rhizome and are often referred to as “running” grasses. These can be invasive and quickly get out of control in a landscape design. One method for containment is to plant the grass inside a large 5-gallon plastic container with the bottom cut out. However, eventually as the plant matures, rhizomes might still find their way out the bottom and come up somewhere else. Be cautious when using these varieties--they are better suited to forming privacy screens or property borders where they are free to expand. Blue lymegrass (Elymus arenarius), Cordgrass (Spartina), and Ribbongrass (Phalaris arundinacea, aka Reed canary grass, Gardener’s garters) are aggressive, but very attractive.
Caring for Ornamental Grasses
Once established, most ornamental grasses need very little attention, except for spring cleanup and division, when required. A newly planted clump of grass should be watered thoroughly and often through the first season; after that, their root systems have bored deeply into the soil and they will need very little, if any irrigation. During extreme drought conditions, some species will need additional water.
In spring, well before the weather warms and the new growth begins, cut the dried stalks back to about 6 inches. This can also be done in the fall after the foliage has dried. Small grass clumps are easy to cut back, but the larger ones often require tying the foliage with cord or a bungee, then sawing through the base. Any way you do it, you’ll have a bit of a mess--one of the only drawbacks to ornamental grasses.
When a mature clump begins the spring with only an outer circle of new growth, it’s time to divide the clump. The empty center of the clump is a combination of dead roots and foliage, and the plant will not re-grow from this area. Dividing a large clump of grass takes a lot of effort and strength, and sometimes a sharp axe! Clumps of about 2 feet in diameter can be divided into two new plants; clumps measuring 3 to 4 feet across will provide four to five new plants.
Dig the entire plant out of the ground before cutting it into sections. Clean each section, removing the dead material, then replant. Water well through the first season.
Add some waves of green to your own landscape and enjoy it for years to come.
North Carolina State University College of Agriculture and Life Sciences, Hort on the Internet