Masses of Grass: Planting Large Groupings Of Ornamental Grasses
by David Salman
Chinese Maiden Hair Grass with a mass planting of Lavender
Ornamental grasses are some of our very best garden plants. They're low care perennials with a big impact on the look of our landscapes. With their fine-textured foliage, attractive flowers and seed heads, graceful movement in the breeze along with extended fall and winter beauty, they give us a remarkable visual contrast with flowering perennials, shrubs and other garden plants.
But ornamental grasses look best when used in larger numbers. How often do you see a prairie or meadow with just one grass plant?
Follow David Salman's recommendations for gorgeous mass plantings with Ornamental Grass. With these tips, you can create a breathtaking garden that is low maintenance, yet still has a major visual impact.
Ornamental Grass Garden with Nassella tenuissima and Little Bluestem grasses combine for an informal planting style at the Denver Botanic Garden in autumn.
Massing: Formal & Geometric, or Informal & Natural?
Grasses are accustomed to growing in groups, which in gardening terminology is referred to as "massing." Massing can also refer to planting large numbers of grass plants (without other non-grass plants) to create dramatic geometric 3-D patterns. This can be accomplished in both formal and informal ways. Grasses lend themselves to being planted in pleasing geometric patterns or simply grouped together in less formal arrangements.
Blonde Ambition Blue Grama Grass works for formal plantings as shown in this municipal landscape planting in New Mexico.
Designing Formal, Geometric Plantings With Grass
For structured plantings, follow these key guidelines:- Use long-lived species and cultivars. Short-lived varieties like blue Festuca ovina cultivars and Nassella (Silky Thread Grass) are not good choices.
- Use grasses that don't reseed themselves to any large extent. Otherwise, they quickly fill in between the original plants and destroy the planting pattern.
- Use grasses that grow as clumps, not ones that spread to create large mats via stolons (arching stems that push from the center of the grass and develop roots at the nodes where they touch the ground). Leymus arenarius and related species are "runners." These grasses are best used to cover slopes, beaches, and other larger areas.
- Stick with one grass variety to accentuate the visual impact by creating uniformity of the planting. However, two or three types of grasses can be combined by planting differently-sized grasses in geometric grid patterns that are placed side by side.

Blonde Ambition Blue Grama Grass planted with Pink Flamingo Mulhy Grass perfectly play off each other with their attractive foliage, and bright plumes.
Foer example, I've seen formal plantings of Nassella tenuissima (Silky Thread Grass) that for a couple of growing seasons, looked really nice. But Nassella is not a long-lived species, which for a geometric mass planting, is not good. By the third year, some of the original plants had died and there were a lot of volunteer seedlings that had filled in between the original plants. Thus the geometric unity of the design was ruined by gaps in the original grid and in-fill from volunteer seedlings.
Recommended Long-Lived, Low-Reseeding Grasses For Formal, Geometric Groupings:
- Bouteloua gracilis 'Blonde Ambition' (Blue Grama Grass)
- Calamagrostis acutiflora ('Karl Foerster' and variegated cultivars)(Feather Reed Grass)
- Helictotrichon sempervirens (Blue Avena Grass)
- Muhlenbergia dubia (Pine Muhly Grass)
- Muhlenbergia 'Pink Flamingo' (Hybrid Muhly Grass)
- Panicum virgatum cultivars ('Heavy Metal', 'Ruby Ribbons', 'Shenandoah'), Schizachyrium scoparium 'Standing Ovation' (Little Bluestem Grass)
- Sorghastrum nutans 'Thin Man' (Blue Indian Grass)
Caradonna Sage (Salvia) and Magnus Purple Coneflowercombine beautifully with Ruby Muhly Grass in this Sonoma, CA garden.
Designing Informal, Natural Plantings With Grass
For informal plantings, there is much more latitude. Informal designs allow the gardener to use a variety of grass species and cultivars, that are grouped in non-geometric patterns. Informal plantings accommodate shorter lived types, varieties that re-seed themselves and stoloniferous types along the edges. The gardener needs to do some "editing" each spring to thin out volunteer seedlings, so the planting doesn't become too dense and too much of a scrambled mixture.
There are so many possible combinations that will beautify the garden. But be sure that you used odd numbers of each grass (3,5,7) planted together. Mix the groups of one type with groups of other types. One each, of many different kinds of grass creates a hodge-podge design with no visual focal points on which the eye can rest. Use shorter types masses around groups of larger growers. It is also permissible to include groupings of larger growing perennial flowers to provide color and contrast. Prairie species of flowering perennials are always a good choice.
White Cloud Muhly Grass is a hard-to-find ornamental grass which thrives in both heat and humidity. This perennial grass is perfect for plantings of atleast three.
Recommended Grasses For Informal, Naturalizing Plantings:
Create habitat for butterfly/moth caterpillars and seed-eating songbirds by using native species and cultivars. Look for these grass species:
- Sorghastrum nutans (Indian Grass)
- Panicum virgatum (Prairie Switch Grass)
- Schizachyrium (Little Bluestem Grass)
- Andropogon (Big Bluestem Grass)
- Muhlenbergia (Muhly Grass)
- Bouteloua gracilis 'Blonde Ambition' (Blue Grama Grass)
- Sporobolus wrightii 'Windbreaker' (Giant Sacaton Grass)
- Muhlenbergia reverchoniii (Undaunted® Ruby Muhly)
Shop Ornamental Grass
Pink Flamingo is one of the most spectacular native grasses for its big size, thin evergreen leaves and bright pink flower plumes that cover the grass in late summer. A heat loving...
Learn MorePink Flamingo Muhly Grass Pink Flamingo Muhly Grass Muhlenbergia Pink FlamingoAs low as $14.99 Sale $14.24Per Plant - 5" Deep PotPink Flamingo is one of the most spectacular native grasses for its big size, thin evergreen leaves and bright pink flower plumes that cover the grass in late summer. A heat loving hybrid discovered in Texas. Drought resistant/drought tolerant plant (xeric).Learn MoreBlonde Ambition Blue Grama Grass (Bouteloua gracilis Blonde Ambition PP#22,048) is a native ornamental grass with a completely new look. The horizontal eyelash-like chartreuse flower...
Learn MoreBlonde Ambition Blue Grama Grass Blonde Ambition Blue Grama Grass Bouteloua gracilis Blonde Ambition PP#22,048As low as $11.99 Sale $11.39Per Plant - 5" Deep PotLearn MoreBlonde Ambition Blue Grama Grass (Bouteloua gracilis Blonde Ambition PP#22,048) is a native ornamental grass with a completely new look. The horizontal eyelash-like chartreuse flowers appear in mid-summer and age to blonde seed heads by fall. They are held on the plant right through the winter to provide many months of interest. 2011 Plant of The Year
Sporobolus wrightii Windbreaker (Lunas Form of Giant Sacaton Grass) is the largest of all our native grasses growing to enormous size at maturity. Blooming in mid-summer, the flower...
Learn MoreWindbreaker Giant Sacaton Grass Giant Sacaton Grass Sporobolus wrightii Windbreaker (Los Lunas Form)As low as $11.99 Sale $10.79Per Plant - 5" Deep PotSporobolus wrightii Windbreaker (Lunas Form of Giant Sacaton Grass) is the largest of all our native grasses growing to enormous size at maturity. Blooming in mid-summer, the flower spikes vary in color from blonde to bronze. This ornamental grass is a drought resistant/drought tolerant perennial plant (xeric). Exclusive.Learn MoreThe world's most popular ornamental grass, 'Karl Foerster' has a strong upright habit and blooms with showy flowers that ripen to tawny seed heads that decorate the plant through the...
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Learn MoreUndaunted® Ruby Muhly Grass Undaunted® Ruby Muhly Grass Muhlenbergia reverchonii PUND01SAs low as $10.99 Sale $10.44Per Plant - 5" Deep PotUndaunted® Ruby Muhly Grass (Plant Select) has an impressive late summer display of see-through amber-pink flower spikes. This is the one Muhly grass with showy pink flowering plumes that can be grown in USDA zones 5 and 6. A High Country Gardens introduction. Drought resistant/drought tolerant plant (xeric).Learn MoreAppalachian Sedge (Carex appalachica) is a native grass-like plant with thin, fine-textured leaf blades. Appalachian Sedge is an outstanding choice for use as an attractive grassy gr...
Learn MoreAppalachian Sedge Grass Appalachian Sedge Carex appalachicaAs low as $9.99 Sale $9.49Per Plant - 3.25" PotAppalachian Sedge (Carex appalachica) is a native grass-like plant with thin, fine-textured leaf blades. Appalachian Sedge is an outstanding choice for use as an attractive grassy groundcover for shade and heavy shade areas.Learn MoreOur Grama Grass Collection features three ornamental grasses, some of our very best garden plants. With their fine-textured foliage, attractive flowers and seed heads, and graceful m...
Learn MoreGrama Grass Collection Grama Grass Collection Bouteloua Collection$96.91 Sale $92.06Sale Price I Save 5%Per Collection of 9Our Grama Grass Collection features three ornamental grasses, some of our very best garden plants. With their fine-textured foliage, attractive flowers and seed heads, and graceful movement in the breeze, they give us a remarkable visual contrast with flowering perennials and shrubs. Create a sophisticated mass planting, or create a backdrop to your flower garden. Even past the flowering season, you can enjoy their texture and beauty in fall and winter. These native grasses also provide habitat for birds and insects, and are host plants for several moths and butterflies. Collection of 9 plants.Learn MoreHairy Grama Grass (Bouteloua hirsuita) is a small-growing native grass that thrives in poor soils and blooms in summer with cheery eyelash-like flowers. This xeric plant is an excell...
Learn MoreHairy Grama Grass Hairy Grama Grass Bouteloua hirsuita$11.99 Sale $11.39Sale Price I Save 5%Per Plant - 2.5" PotHairy Grama Grass (Bouteloua hirsuita) is a small-growing native grass that thrives in poor soils and blooms in summer with cheery eyelash-like flowers. This xeric plant is an excellent addition to waterwise gardens, for groundcover and textural accents that provide visual interest year-round. It will reseed and naturalize over time, but is not appetizing to deer.Learn More
Text and Photos by Founder and Chief Horticulturist David Salman.
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