Masses of Grass: Planting Large Groupings Of Ornamental Grasses

by David Salman

Chinese maiden hair with lavender
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 Naseella and Little Bluestem
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.

Ornamental Grass With Blonde Ambiation Grass
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.
Pink Flamingo Mulhy Grass with Blonde Ambition Blue Grama Grass
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:


Caradonna Sage with Magnus Purple Coneflower
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.

Mulenbergia White Cloud
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:


Shop Ornamental Grass

  1. Pink Flamingo Muhly 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 More
    Pink Flamingo Muhly Grass Pink Flamingo Muhly Grass Muhlenbergia Pink Flamingo
    As low as $14.99 Sale $11.99
    Per Plant - 5" Deep Pot
    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 hybrid discovered in Texas. Drought resistant/drought tolerant plant (xeric).
    Learn More
  2. Deschampsia cespitosa ‘Goldtau’, Gold Dew Tufted Hair Grass, Photo Courtesy Of Hoffman Nursery

    Gold Dew Tufted Hair Grass (Deschampsia cespitosa ‘Goldtau’) is a colorful, fine textured native grass loved for its profuse display of misty, golden flowers and attractive seed ...

    Learn More
    Gold Dew Tufted Hair Grass Gold Dew Tufted Hair Grass Deschampsia cespitosa Goldtau
    As low as $10.99 Sale $8.79
    Per Plant - 3.25" Pot
    Gold Dew Tufted Hair Grass (Deschampsia cespitosa ‘Goldtau’) is a colorful, fine textured native grass loved for its profuse display of misty, golden flowers and attractive seed heads that hold through winter.
    Learn More
  3. Bouteloua gracilis Blonde Ambition, Blonde Ambition Blue Grama Grass

    Blonde 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 More
    Blonde Ambition Blue Grama Grass Blonde Ambition Blue Grama Grass Bouteloua gracilis Blonde Ambition PP#22,048
    As low as $11.99 Sale $9.59
    Per Plant - 5" Deep Pot

    Blonde 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

    Learn More
  4. Sporobolus wrightii Windbreaker Photo Courtesy of Plant Select

    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 More
    Windbreaker Giant Sacaton Grass Giant Sacaton Grass Sporobolus wrightii Windbreaker (Los Lunas Form)
    As low as $11.99 Sale $9.59
    Per Plant - 5" Deep Pot
    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 spikes vary in color from blonde to bronze. This ornamental grass is a drought resistant/drought tolerant perennial plant (xeric). Exclusive.
    Learn More
  5. Schizachyrium scoparium Standing Ovation

    Standing Ovation Little Bluestem Grass (Schizachyrium scoparium 'Standing Ovation' PP25,202) is an outstanding selection chosen for its blue foliage, reddish fall color and strong up...

    Learn More
    Standing Ovation Little Bluestem Grass Standing Ovation Little Bluestem Grass Schizachyrium scoparium Standing Ovation
    As low as $12.99 Sale $10.39
    Per Plant - 3.25" Pot
    Standing Ovation Little Bluestem Grass (Schizachyrium scoparium 'Standing Ovation' PP25,202) is an outstanding selection chosen for its blue foliage, reddish fall color and strong upright growth habit. Widely adapted for planting across the US. 2018 Plant of The Year
    Learn More
  6.  Calamagrostis acutiflora Karl Foerster, Calamagrostis acutiflora Karl Foerster, Karl Foerster Feather Reed Grass with Rudbeckia

    The 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...

    Learn More
    Karl Foerster Feather Reed Grass Karl Foerster Feather Reed Grass Calamagrostis acutiflora Karl Foerster
    As low as $11.99 Sale $9.59
    Per Plant - 3.25" Pot
    The 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 fall and winter months.
    Learn More
  7. Muhlenbergia reverchonii Photo Courtesy of Plant Select

    Undaunted® 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 pl...

    Learn More
    Undaunted® Ruby Muhly Grass Undaunted® Ruby Muhly Grass Muhlenbergia reverchonii PUND01S
    As low as $10.99 Sale $8.79
    Per Plant - 5" Deep Pot
    Undaunted® 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 More
  8. Carex appalachica, Appalachian Sedge, Photo Courtesy Of Hoffman Nursery

    Appalachian 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 More
    Appalachian Sedge Grass Appalachian Sedge Carex appalachica
    As low as $9.99 Sale $7.99
    Per Plant - 3.25" Pot
    Appalachian 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 More

Text and Photos by Founder and Chief Horticulturist David Salman.

© All articles are copyrighted by High Country Gardens. Republishing an entire High Country Gardens blog post or article is prohibited without written permission. Please feel free to share a short excerpt with a link back to the article on social media websites, such as Facebook and Pinterest.