Rabbitbrush, Ornamental Grasses, and Russian SageRabbitbrush, Ornamental Grasses, and Russian Sage

Fall Garden Cleanup: Don't Prune These

Maintaining Our Gardens To Maximize Their Value As Habitat

by David Salman, Chief Horticulturist & Founder of High Country Gardens

Fall is well underway and many of us are focused on getting our gardens and landscapes ready for their winter rest. With the effects of climate change already impacting our lives, we no longer have the luxury of gardening just for beauty. We must also plant and care for our landscapes to benefit the creatures that share our environment. We can do this by providing habitat, supported by our plant choices and maintenance methods. Here is some guidance as to which plants need to be cut back in fall or winter and which should be left standing until spring to make your garden and landscape more "habitat friendly."

Read on for tips in all areas of your garden:

New Mexico Privet, Russian Sage, and Mountain Pine In OctoberNew Mexico Privet, Russian Sage, and Mountain Pine In October
New Mexico Privet, Russian Sage, and Mountain Pine In October

Deciduous Shrubs & Trees

Winter is an ideal time for pruning deciduous plants (woody plants that lose their leaves), because they are dormant.

  • Most fruit, flowering, and shade trees all benefit from winter pruning. This will help to remove crossed branches, gently shape their branch structure, and, with shade trees, help to maintain strong non-forked leaders.
  • Don't shear the branches of spring flowering shrubs (Forsythia, Lilac, New Mexico Privet, Spirea, Flowering Quince, and others). These shrubs produce flowers on last year's wood, so removing old growth will reduce or prevent flowering. These plants should be pruned immediately after they are done blooming. 
  • Summer blooming shrubs like Russian Sage (Perovskia), Spirea (Caryopteris), and Butterfly Bush (Buddleia davidii and hybrids) should be left untrimmed over the winter months.
    • Russian Sage should be cut back hard in mid-spring, leaving stems 12-15" tall. This should be done every spring to keep them blooming heavily.
    • Blue Mist Spirea and Butterfly Bush should be cut back by 1/3 to 1/2 of their height every third year (NOT annually) to re-invigorate the shrubs and encourage blooming.

Leaves 

Don't kick this valuable resource to the curb! Leaves are a valuable resource for soil building and mulching. They also provide habitat for pollinators, such as bumblebees and beetles, beneficial insects, and wildlife. 

  • Leaves should be raked from lawns but utilized elsewhere in the landscape. Chopping up leaves will help them break down more easily; rake them and put them through a shredder or use a lawnmower to shred them. They can also be added to your compost pile.
  • Use leaves as mulch under trees, shrubs, and evergreens.
  • Use chopped leaves to mulch perennial beds and vegetable gardens.
  • In wetter climates, it's best not to leave layers of fallen leaves on top of your untrimmed perennials and other flower beds, as they will cause problems with fungus and rot. Instead, chop 'em up and use them as mulch to improve your soil.
Fall Garden With Miscanthus Grass and GoldenrodFall Garden With Miscanthus Grass and Goldenrod
Fall Garden with Miscanthus Grass and Goldenrod

Ornamental Grasses

Why leave ornamental grasses standing? There are many reasons to leave these grasses standing over the winter months. Their foliage and seed heads offer texture, movement, and beauty in the winter; they'll be illuminated by the low angled winter sunshine. Plus, many beneficial insects use these grasses to provide protection for overwintering egg masses, larvae, and adult forms. Leaving ornamental grasses standing until late spring gives the insects time for their eggs to hatch and their larvae to change into adults. Birds will also utilize standing grasses as sources for seed and winter shelter. Ground birds, such as quail, will use large ornamental grasses for winter protection.

Switchgrass sways in the autumn breeze. Sedum and Bald Cypress Trees in the background.

Perennial Plants & Flowers 

Why leave perennial plants & flowers standing over winter months? Like ornamental grasses, it's a good idea to leave perennials standing as well. These plants will often provide the same shelter to beneficial insects as the ornamental grasses. 

Seed bearing perennials such as Purple Coneflower (Echinacea), Joe Pye Weed (Eupatorium), Hummingbird Mint (Agastache), Lavender (Lavandula), perennial Sunflower (Helianthus), and others, also provide valuable winter food for songbirds. Additionally, species with stiff stems and ornamental seed heads, such as Yarrow (Achillea), Purple Coneflower (Echinacea), Tall Stonecrop (Sedum), and others with flat or cone-shaped dried flowers, add to the garden's winter beauty.

Plus, perennials are more cold hardy when their stems are left standing over the winter. This is helpful for overwintering perennials that are living at the edge of their cold hardiness zones. For example, when native Sage (Salvia), Hummingbird Mint (Agastache), and Hummingbird Trumpet (Zauschneria) are planted in USDA zones 5 & 6, this will help them survive the winter cold. This is especially true for young plants (in the ground one to two growing seasons).

  • Wait until mid-spring to cut back perennials.
  • If perennial plants are exhibiting some summer/fall disease or are infested with injurious insects, then in these instances, these damaged plants should be cut back, and scraps thrown away in the trash, not the compost, to prevent the disease or pests from spreading.
  • Learn More: Perennial Plant Care In Seasons 1 & 2

 

Gold Yarrow (Achillea) and Mulhy Grass In OctoberGold Yarrow (Achillea) and Mulhy Grass In October
Yarrow (Achillea) and Mulhy Grass add striking textures in this fall garden.

Lawns & Meadows

  • Native Buffalo Grass and Blue Grama Grass, as well as Dog Tuff lawns, should be given the last mowing in late October.
  • Mow the grass high, leaving it at least 4" tall. Never scalp the lawn in the fall, as this weakens it and leaves the stems vulnerable to damage from cold and dry conditions.
  • Grass meadows and wildflower meadows, like ornamental grasses and perennials, should also be left standing over the winter. Mow with the mower deck set high in mid-spring.

Habitat-Friendly Plants From High Country Gardens

  1.  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...

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    Karl Foerster Feather Reed Grass Karl Foerster Feather Reed Grass Calamagrostis acutiflora Karl Foerster
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    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.
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  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...

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    Blonde Ambition Blue Grama Grass Blonde Ambition Blue Grama Grass Bouteloua gracilis Blonde Ambition PP#22,048
    As low as $6.99 Sale $5.59
    Per Plant - 2.5" 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

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  3. Festuca Siskiyou Blue, Siskiyou Blue Idaho Fescue Grass

    This is a new selection of the native Idaho Fescue, notable for its enticing spruce-blue foliage. The thin leaves are much longer than the more familiar Festuca glauca, giving 'Siski...

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    Siskiyou Blue Fescue Grass Siskiyou Blue Idaho Fescue Grass Festuca idahoensis Siskiyou Blue
    As low as $11.99 Sale $9.59
    Per Plant - 5" Deep Pot
    This is a new selection of the native Idaho Fescue, notable for its enticing spruce-blue foliage. The thin leaves are much longer than the more familiar Festuca glauca, giving 'Siskiyou Blue' a softer, more graceful look.
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  4. 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...

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    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
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Text by Founder and Chief Horticulturist David Salman. 

Banner Image by Saxon Holt, featuring Rabbitbrush (Chrysothamnus), Switchgrass (Panicum virgatum), Silky Thread Grass (Nasella), and Russian Sage (Perovskia)

© 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.

by David Salman

Leave Ornamental Grass standing in the fall for winter interest.

Fall is well underway and many of us are focused on getting our gardens and landscapes ready for their winter rest. Here is some guidance as to which plants need to be cut back in fall or winter and which should be left standing until spring.

Maintaining Our Gardens To Maximize Their Value as Habitat

As I have said many times, with the effects of climate change already impacting our lives, we no longer have the luxury of gardening just for beauty. We must also plant and care for our landscapes to benefit the creatures that share our environment by providing habitat with our plant choices and maintenance methods. Here are some tips that will help to make your garden and landscape more "habitat friendly."

Panicum virgatum 'North Wind' in fall.
Gold Plate Yarrow (Achillea) with Muhly Grass (Muhlebergia) in fall.

Deciduous Shrubs and Trees: Winter is an ideal time for pruning woody plants that lose their leaves (deciduous) because they are dormant.

  • Most fruit, flowering and shade trees all benefit from winter pruning to remove crossed branches, gently shape their branch structure and, with shade trees, maintaining strong non-forked leaders.
  • But don't shear the branches of spring flowering shrubs (Forsythia, Lilac, New Mexico Privet, Spirea, Flowering Quince and others), as this will remove the old wood (last year's growth) that produces flowers in the spring.
  • Summer blooming shrubs like Russian Sage (Perovskia), Blue Mist Spirea (Caryopteris) and Butterfly Bush (Buddleia davidii and hybrids) should be left untrimmed over the winter months.
  • Russian Sage should be cut back hard in mid-spring, leaving stems 12-15" tall. This should be done every spring to keep them blooming heavily.
  • Blue Mist Spirea and Buddleia should be cut back by 1/3 to 1/2 of their height every third year (NOT annually) to re-invigorate the shrubs and encourage blooming.
  1. Buzz® Hot Raspberry Butterfly Bush , Buddleia davidii 'Hot Raspberry', raspberry-pink flowers

    Buzz® 'Hot Raspberry' Butterfly Bush (Buddleia davidii) wakes up summer’s doldrums with splendid raspberry-pink flowers. Blooming from early summer to late fall, the sweetly scent...

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    Buzz® Hot Raspberry Butterfly Bush (Buddleia) Buzz® Hot Raspberry Butterfly Bush Buddleia davidii Hot Raspberry
    $11.99
    Per Plant - 5" Deep Pot
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  2. Buzz® Midnight Butterfly Bush, Buddleia davidii 'Midnight' with two visiting  pollinators

    Buzz® 'Midnight' Butterfly Bush (Buddleia davidii) is an exciting compact butterfly bush with magnificent jewel-tones of rich purple and blue flowers that shower the garden with col...

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    Buzz® Midnight Butterfly Bush (Buddleia) Buzz® Midnight Butterfly Bush Buddleia davidii Midnight
    $11.99
    Per Plant - 5" Deep Pot
    Buzz® 'Midnight' Butterfly Bush (Buddleia davidii) is an exciting compact butterfly bush with magnificent jewel-tones of rich purple and blue flowers that shower the garden with color and a sweet honey scent from early summer to late fall. A powerful attractor of butterflies and hummingbirds, it’s also deer and rabbit resistant. A perfect easy-to-grow upgrade for the perennial bed, container, hedge, or border.
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  3. Littleleaf Mountain Mahogany, Cercocarpus intricatus

    A native shrub from the southwestern US, Littleleaf Mountain Mahogany (Cercocarpus intricatus) features attractive silvery evergreen foliage for year-round interest and bird habitat....

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    Littleleaf Mountain Mahogany (Cercocarpus) Littleleaf Mountain Mahogany Cercocarpus intricatus
    $12.99
    Per Plant - 5" Deep Pot
    A native shrub from the southwestern US, Littleleaf Mountain Mahogany (Cercocarpus intricatus) features attractive silvery evergreen foliage for year-round interest and bird habitat. Its compact size and outstanding durability make it an excellent choice for hedging and xeric landscaping. In mid-spring, the shrub is covered in plumes of tiny pale flowers, which are pollinated by small native bees to create feathery seed tails that catch the afternoon light.
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  4. Claremont Flowering Currant, Ribes sanguineum v. glutinosum 'Claremont', clusters of pink flowers

    A stunning early spring-blooming shrub with pendulous clusters of pink flowers, 'Claremont' Flowering Currant (Ribes sanguineum) is an essential nectar source for bees and migrating ...

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    Claremont Flowering Currant (Ribes) Claremont Flowering Currant Ribes sanguineum var. glutinosum Claremont
    $12.99
    Per Plant - 5" Deep Pot
    A stunning early spring-blooming shrub with pendulous clusters of pink flowers, 'Claremont' Flowering Currant (Ribes sanguineum) is an essential nectar source for bees and migrating hummingbirds. In fall, foliage shifts to a warm apricot hue. Also known as Winter Currant, this California native displays edible inky black berries that attract birds. This fragrant, showy shrub is a great choice for small yards and patio gardens.
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    Ornamental Grasses: Leave these grasses standing over the winter months.

  • Their foliage and seed heads offer us winter beauty when the low angled winter sunshine illuminates them.
  • Wait until mid-spring to cut grasses back, as many beneficial insects use these grasses to provide protection for overwintering egg masses, larvae, and adult forms. This gives the insects time for their eggs to hatch and their larvae to change into adults.
  • Birds will also utilize these standing grasses as sources for seed and winter shelter. Ground birds, like quail, will use large ornamental grasses for winter protection.
  • Warm season grasses include Little Bluestem (Schizachyrium), Big Bluestem (Andropogon), 'Blonde Ambition' Blue Grama (Bouteloua), Muhly (Muhlenbergia), Prairie Switchgrass (Panicum), Chinese Maidenhair Grass (Miscanthus), Giant Sacatoon (Sporobolus wrightii) and others. They should be cut back in mid-spring.
  • Cool season grasses, like Blue Avena Grass (Helictotrichon), Fescue grass (Festuca), Silky thread Grass (Nassella) and 'Karl Foerster' Feather Reed grass (Calamagrostis) have evergreen foliage that should not be cut to the ground. Instead vigorously "comb out" dead leaves with gloved hands and clip off the dead leaf tips. In early spring, clip off old seed head stalks as far down into the foliage as possible to leave room for late spring flowers.
  • If the grass plant has a ring of living leaves with a dead center, it's time to divide the grasses to re-invigorate them. (This is necessary once every three to five years depending on the species and growing conditions.)

Perennials: Also leave perennials standing as well.

  • These plants will often provide the same shelter to beneficial insects as the ornamental grasses.
  • Additionally, species with ornamental seed heads such as Yarrow (Achillea), Purple Coneflower (Echinacea), Tall Stonecrop (Sedum) and others with flat or cone-shaped dried flowers, add to the garden's winter beauty.
  • Seed bearing perennials such as Purple Coneflower (Echinacea), Joe Pye Weed (Eupatorium), Hummingbird Mint (Agastache), Lavender (Lavandula), perennial Sunflower (Helianthus) and others provide valuable winter food for songbirds.
  • Perennials that are living at the edge of their cold hardiness are more cold hardy when their stems are left standing over the winter. So when native Sage (Salvia), Hummingbird Mint (Agastache), Hummingbird Trumpet (Zauschneria) are planted in USDA zones 5 & 6, this will help them survive the winter cold. This is especially true for young plants (in the ground one to two growing seasons).
  • Wait until mid-spring to cut back perennials, unless the perennial plants are exhibiting some summer/fall disease or are infested with injurious insects. In these instances, these damaged plants should be cut back.

Leaves: Leaves are a valuable resource for soil building and mulching. Don't just throw them away.

  • They should be raked from lawns, but utilized elsewhere in the landscape where they can be used as mulch under trees, shrubs and evergreens. Or rake them and put them through a shredder, so you can mulch perennial beds and vegetable gardens with the chopped-up foliage.
  • In wetter climates, it's best not to leave them on top of your untrimmed perennials and other flower beds as they will cause problems with fungus and rot. Instead, chop 'em up and use them as mulch to improve your soil.
  • Red Happiness Agastache with Sipa gigantea and Chilopsis in seed.

Grass Meadows and Lawns:

  • Native (Buffalo and Blue Grama Grass) and Dog Tuff lawns should be given a last mowing in late Oct. But mow the grass high, leaving it about 4" tall. Never scalp the lawn in the fall as this weakens it and leaves the stems vulnerable to damage from cold and dry conditions.
  • Meadows, like ornamental grasses and perennials, should also be left standing over the winter. Mow with the mower deck set high in mid-spring.
Gold Plate Yarrow (Achillea) with Muhly Grass (Muhlebergia) in fall.
Gold Plate Yarrow (Achillea) with Muhly Grass (Muhlebergia) in fall.

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.

  1. Blanca Peak™ Rocky Mountain Beard Tongue, Penstemon strictus ‘WWG06’

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