Karl Foerster Ornamental GrassKarl Foerster Ornamental Grass

Enjoying The Tall Grasses Of Late Summer & Fall

By David Salman, Chief Horticulturalist and Founder of High Country Gardens

The Spring garden usually consists of smaller growing plants; those that wake up early, grow and bloom with the cool conditions of the start of the growing season. The fall is the time for the big plants to take center stage, having had the whole summer to reach flowering size. Many of the most dramatic plants in the late season garden would have to be the ornamental grasses. With their large size and interesting flowering spikes, these grasses have no equal when it comes to reflecting the glow of sunlight late in the day. And the grace of their swaying stems in the slightest breeze brings movement to the landscape.

Warm & Cool Season Grasses

All of the ornamental grasses are good candidates for fall planting, and you'll get a head start on next spring's growth. Know that the warm season growers won't show a lot of top growth, as their energies will be spent growing roots. The cool season growers will show both above and below ground growth. Grasses are loosely divided between cool season growers and warm season growers.The cool season grasses include:

The warm season growers include many of our native prairie grasses, such as:

Blonde Ambition Blue Grama Grass has unique eyelash-like seedheads that gracefully capture the light.Blonde Ambition Blue Grama Grass has unique eyelash-like seedheads that gracefully capture the light.
Blonde Ambition Blue Grama Grass has unique eyelash-like seedheads that gracefully capture the light.

Plant Combinations With Ornamental Grasses  

When considering the addition of warm season grasses to your landscape, it's nice to know that they are outstanding companion plants to a variety of herbaceous perennials and smaller flowering shrubs. Their presence with perennials immediately captures your attention. In fact, many of the large growing ornamental grasses are great shrub companions for creating an interesting but very low care landscape. They are a great choice for the casual gardener.

Agastache Ava and Muhly Grass In OctoberAgastache Ava and Muhly Grass In October
Agastache Ava and Muhly Grass In October

Fall Care Of Ornamental Grasses

Don't cut them back in the fall! The most common mistake I see with ornamental grasses happens when they're cut back in fall as part of fall garden clean-up. This robs you of their beauty over the fall and winter months which is a big part of their usefulness, especially in climates with long, dreary winters.

  • For warm season growers, wait until mid-spring and cut them back HARD (leaving only 2-4" inches above ground).
  • For cool season growers, trim off the faded seed heads and comb out the foliage to rid it of brown foliage. But whenever possible avoid cutting them back near ground level like their warm season cousins.
  • Fertilize in mid-fall with a top dressing of Yum Yum Mix Winterizer and compost around the base of the grass. Scratch it in, re-apply some mulch and water thoroughly.

Shop Ornamental Grasses

  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...

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    Pink Flamingo Muhly Grass Pink Flamingo Muhly Grass Muhlenbergia Pink Flamingo
    As low as $14.99 Sale $14.24
    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. 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 $10.79
    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
  3. 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...

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    Windbreaker Giant Sacaton Grass Giant Sacaton Grass Sporobolus wrightii Windbreaker (Los Lunas Form)
    As low as $11.99 Sale $11.39
    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
  4.  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 $11.39
    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

by High Country Gardens

Stipa gigantea
Stipa gigantea

The Spring garden usually consists of smaller growing plants; those that wake up early, grow and bloom with the cool conditions of the start of the growing season. The fall is the time for the big plants to take center stage, having had the whole summer to reach flowering size. Many of the most dramatic plants in the late season garden would have to be the ornamental grasses. With their large size and interesting flowering spikes, these grasses have no equal when it comes to reflecting the glow of sunlight late in the day. And the grace of their swaying stems in the slightest breeze brings movement to the landscape.

The Warm and Cool of It

All of the ornamental grasses are good candidates for fall planting and you'll get a head start on next spring. Know that the warm season growers won't show a lot of top growth, as their energies will be spent growing roots. The cool season growers will show both above and below ground growth.

Grasses are loosely divided between cool season growers and warm season growers. The cool season clan includes:

Bouteloua Blonde Ambition
Bouteloua Blonde Ambition

The warm season growers include many of our native prairie grasses, such as:

Combinations with Ornamental Grasses

When considering the addition of warm season grasses to your landscape, it's nice to know that they are outstanding companion plants to a variety of herbaceous perennials and smaller flowering shrubs. Their presence with perennials immediately captures your attention.

Muhlenbergia Pink Flamingo-
Muhlenbergia Pink Flamingo

The warm season growers include many of our native prairie grasses, such as:

When planted with smaller growing shrubs such as summer blooming Blue Mist Spirea (Caryopteris) and fall blooming Rabbit Brush (Chysothamnus), Maiden Hair Grass is especially showy. In fact, many of the large growing ornamental grasses are great shrub companions for creating an interesting but very low care landscape. They are a great choice for the casual gardener.

Care of Ornamental Grasses

Don't cut them back in the fall! The most common mistake I see with ornamental grasses happens when they're cut back in fall as part of fall garden clean-up. This robs you of their beauty over the fall and winter months which is a big part of their usefulness, especially in climates with long, dreary winters.

  • For warm season growers, wait until mid-spring and cut them back HARD (leaving only 2-4" inches above ground).
  • For cool season growers, trim off the faded seed heads and comb out the foliage to rid it of brown foliage. But whenever possible avoid cutting them back near ground level like their warm season cousins.
  • Fertilize in mid-fall with a top dressing of Yum Yum Mix Winterizer and compost around the base of the grass. Scratch it in, re-apply some mulch and water thoroughly.

Text and Photos by David Salman.

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