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Pretty Perennial Ornamental Grasses For Late Summer

Blue fescues are lovely, steely blue grasses that form tidy clumps.

It’s August and here in Indiana we often have days in the 90s.  Many summer perennials, such as daylilies, salvias, and Shasta daisies, are past their prime or have disappeared until next year. Perennial garden grasses, however, are still colorful with their bold plumes and blades. There are many species and varieties available to fit practically any garden.

Perennial grasses range from the diminutive (1-foot or less) to big and bold (6-8 feet or more). Some are dense and colorful while others are airy and textural. Most require full sun, but some will grow well in partial shade. I only grow perennial grasses, so I do not have to fuss with planting new ones every spring. Here are some of my favorites for your consideration.

Sterile Chinese Maiden Grasses

Maiden grasses (Miscanthus sinensis, Zones 5-9) are beautiful, but gardeners need to exercise caution when choosing one. Many of these Asian-native grasses are invasive to North America, so it is best to choose varieties with low or no seed set. One of my favorites Miscanthus is the 6-foot-tall ‘Zebra Grass’, which has an unusual pattern of horizontal-striped bands of yellow across the green blades, but it is not sterile. Thankfully, they have come out with the smaller 3-foot-tall ‘Bandwidth‘, which has all of the good looks while being infertile. In late summer it sends up feathery, golden-brown plumes that produce no fluffy seeds.

Another beautiful, yet invasive, variety is the 6-foot-tall, graceful ‘Morning Light’ with its narrow, green blades with white edges and midveins. The clump reflects light, giving the plant a shiny appearance. The reliably sterile My Fair Maidenis a good replacement. It reaches a whopping 6-8 feet and has very showy plumes that glisten in the sun.

Maiden grasses do best in full sun and need regular water since they don’t like dry soil. Give them plenty of space to grow. These clump-forming grasses widen with age. If you want a tall hedge but don’t want to wait around for slow-growing shrubs or trees, plant maiden grasses instead. They are fast-growing and dense. Wear long-cuffed gardening gloves when you cut the old clumps back to 18 inches in early spring.

Switchgrass

Cheyenne Sky has blades that turn shades of red. (Image thanks to Proven Winners)

A simply gorgeous native switchgrass (Panicum virgatum, Zones 4-9) variety from Proven Winners is Cheyenne Sky. The deer-resistant grass forms a tight, upright clump of blue-green leaves that turn wine-red in early summer and stay that way until frost. It needs full sun and is drought-tolerant once established. At only 3 feet tall, it looks beautiful in large containers as well as in the garden. The clumps spread over time. Leave the dry blades and airy panicles for winter beauty and cut them back in late winter before they begin growing again.

Muhly Grass

Muhly grass has pink plumes that are wonderfully showy.

An unusual and extra-beautiful grass for fall color is the pink muhly grass (Muhlenbergia capillaris, Zones 5-9), or pink hair grass, which is native to barrens and prairies of the eastern United States. In fall, it sends up large, 12-inch, frothy, panicles that look like bright pink clouds. These can last from September to November.  The leaves are very narrow and shiny. Pink hair grass reaches up to 3 feet tall, likes well-drained soil, and is drought tolerant once established. It looks best when planted in groups and grows best in full sun but will tolerate more shade than other grasses. Regal Mist® is an extra showy variety to try.

Blue Fescue

Blue fescue is semi-evergreen, so it continues to look outstanding in winter.

Blue fescue (Fescue glauca, Zones 4-11) is a wonderful compact ornamental grass for the front of the flower garden. It is round clump-forming grass with straight, narrow, blue blades. At only 8-12 inches tall (foliage) it is one of the shortest ornamental grasses.  It is drought tolerant and does well in rock gardens or any other dry-soil area.  Blue fescue sends up its flower heads in late spring–by summer they turn tan. Two excellent varieties are ‘Elijah Blue’ and ‘Boulder Blue’. Old specimens plant sometimes die back in the center. At this time, divide them to rejuvenated clumps, and replant them elsewhere.

Red Hood Sedge

For interest, I decided to add one sedge to the list–sedges being close relatives of grasses. Red hood sedge (Uncinia rubra, Zones 7-10) is a stunning evergreen sedge species from New Zealand that is so tempting to me. The beautiful, cascading, 1-foot mounds have bright, glossy, red blades. Red Hood Sedge will grow in full sun or full shade, so you can tuck them in among your hostas. It grows well but does not require, very wet soil, so it can be planted where other grasses would probably not make it. Choose a spot or pot with moist, rich soil, and do not let it get too dry.  An excellent variety is ‘Everflame’, which has undulating red blades.

Fall Garden Flowers of the Prairies

The golden strands of the prairie native, wrinkleleaf goldenrod, look right at home in a fall flower garden.

So many favorite summer garden flowers were originally natives of the American prairies–purple coneflowers, black-eyed-Susans, and blazing star among them. Fall is no exception. Whether you plant wild forms or garden varieties, flowers of the prairie are generally easy, tough landscape plants. (If they could withstand trampling and grazing by elk and buffalo, they surely can grow well in your garden!) Some can be planted now, while others can be added to your plant list for next spring.

It’s never too late or early to start thinking about next year’s flower garden, and late summer and fall is the time to see what’s looking beautiful or not-so-great in your garden. Look for holes where a little more color and interest could do some good. You might also make space by removing or thinning out any disappointing or overcrowded plants. Once space has been made, plant now or plan for next spring.

Fall Garden Flowers with Prairie Origins

Native prairie in Lake County, Illinois looks almost planted with its colorful New England asters and Canada goldenrod.

All of these stellar garden plants have their origins from native prairie wildflowers of North America and grow best in full sun and fertile to average soil with good drainage. Feed beds with organic matter yearly to keep your garden soil and plants happy. Black Gold Garden Soil or Flower & Vegetable Soil are excellent amendments for tired beds in need of a boost.

Fall Asters

Alma Potschke New England aster has brilliant reddish-pink, semi-double flowers

Perennial asters are favorite fall flowers, and most originate from American grass and prairie lands.  Their little daisies can be single, double, or even puffed and come in purple, violet-blue, white, reddish-purple, or shades of pink and lavender. There are many notable species. Of these, I like the tall New England Aster (Symphyotrichum novae-angliae, 2-6 feet, USDA Hardiness Zones 3-8) with its bright purple daisies and ability to grow in both moist and dry soils. Aromatic aster (Aster oblongifolius, 2-6 feet, USDA Hardiness Zones 5-8), which is tolerant of poorer soil, is another winner with its fragrant foliage and lavender-blue flowers with golden centers.

Exceptional varieties include the classic Purple Dome New England aster (Symphyotrichum novae-angliae ‘Purple Dome’, 18 inches x 12-24 inches), which is compact and has the deepest purple flowers that bloom in midfall. The taller Alma Potschke New England aster ( Symphyotrichum novae-angliae ‘Alma Potschke’, 3-4 feet) has a wealth of semi-double flowers of reddish-pink. The cool October Skies aromatic aster (18 inches x 18 inches) bears a dense display of lavender-blue flowers with yellow centers on compact plants. Butterflies, birds, and bees love asters, but deer don’t.

Goldenrod

Fireworks wrinkleleaf goldenrod shines alongside a planting of mums and ornamental peppers at Longwood Gardens. (Image by Jessie Keith)

Most associate the name Goldenrod with tall field weeds, but they are not weeds at all. (And, forget the old wive’s tale that they cause seasonal allergies; goldenrods bloom at the same time as allergy-causing ragweed, hence the confusion.) Nurseries have developed some beautiful varieties, worth planting in your garden for fall color. One of these is Golden Fleece goldenrod (Solidago sphacelata ‘Golden Fleece’, 2 feet x 3 feet, Zones 4-9), which becomes heavily adorned with cascading streamers of bright golden flowers from the middle of September through October. Plant it in full sun and average to dry soil, then sit back and enjoy the butterflies. Trim off old flowers to encourage new ones. ‘Golden Fleece’ is deer resistant.

For a bolder statement try the Fireworks wrinkleleaf goldenrod (Solidago rugosa ‘Fireworks’, 3-4 feet, Zones 4-9) with its impressive sprays of golden flowers that explode in mid-fall. Plant it towards the back of a border beside tall ornamental grasses, tall mums, and Joe-Pye weed.

Sunflowers and Oxeye Daisies

‘Tuscan Sun’ oxeye daisy is very pretty and heavy flowering. (Image by Jessie Keith)

Perennial sunflowers (Helianthus spp.) and oxeye daisies (Heliopsis spp.) look similar, but oxeyes often bloom earlier and continue flowering into fall. One of my favorites is Burning Hearts oxeye daisy (Heliopsis helianthoides var. scabra ‘Burning Hearts’, 3-4 feet, Zones 3-9), a particularly colorful and long-blooming variety that flowers from midsummer to mid-fall. It has purplish leaves and black stems that hold 3-inch flowers of gold with fire-red centers that fade to bronze.  Another excellent choice is Proven Winners’ all-gold ‘Tuscan Sun’ (2-3 feet, Zones 3-9). Be sure to water oxeyes during dry periods, and plant them in full sun. Bees and butterflies cannot get enough of these flowers.

The compact Autumn Gold willowleaf sunflower (Helianthus salicifolius ‘Autumn Gold’, 2-3 feet, Zones 5-10) has a mounding, mum-like habit and becomes covered with sunny, yellow flowers in mid to late fall. Leave the nutritious seed heads for foraging birds.  Once established, ‘Autumn Gold’ will tolerate wet or dry soil conditions, likes full sun, and is deer resistant.

Joe-Pye-Weed

Joe-Pye-weed is an excellent garden flower for feeding migrating Monarchs.

Spotted Joe-Pye weed (Eupatorium maculatum, 3-7 feet, Zones 4-8) is a bold garden perennial that flowers from late summer to fall and commonly inhabits moist prairies. The wild form is useful in big garden borders alongside ornamental grasses, hardy hibiscus, and tall perennial sunflowers. Tamer options also exist. ‘Phantom’ is a maculatum hybrid that only reaches 4 feet tall and produces lots of puffy purplish-pink flowers on tidy, well-branched plants. They grow well in average to moist soil, full sun, and are a favorite of butterflies but not deer.

Muhly Grass

Beautiful pink Muhlenbergia capillaris has magnificent fall grass plumes.

The prairie-native muhly grass (Muhlenbergia capillaris, 2-3 feet, Zones 6-9) is a tough, fall-blooming grass, with cloud-like puffy seed heads or rose or pink. An excellent variety is Regal Mist® with its ruby-pink clouds of grass plumes in fall that are still showy into winter.  It reaches 4-feet tall, does well in any well-drained soil, and is drought tolerant.  Plant muhly grass in full sun. Even though it is a grass, it is deer resistant.

Another fall grass for prairie gardens is Proven Winners’ Prairie Winds® ‘Blue Paradise’ little bluestem. The neat, upright bunch grass just reaches 3-4 feet and has steely blue blades that turn purple in fall. Leave it uncut for winter interest.

Sedums

Rock ‘N Round™ ‘Popstar’ Sedum looks pretty along the edge of any fall bed.

There are some prairie sedums, though few to none are commonly available to gardeners, so I am improvising with a favorite garden variety.  Rock ‘N Round ‘Popstar’ (10-12 inches, Zones 3-9) is an excellent mounding stonecrop with loads of pink flowers late in the season, and purplish-gray leaves the rest of the growing season. Low-growing, fall-blooming stonecrops like Rock ‘N Round look beautiful when planted along the margins of a prairie-inspired garden.  The succulents have thick leaves that hold water and are tolerant of hot, dry spells. Most new varieties have fancy leaves that are beautiful all season long. Sedums are generally deer resistant.

When planting any of these fall beauties, dig a hole twice as large as the roots, incorporate a few handfuls Black Gold Garden Soil into the backfill.  Then plant your perennial. Follow up by adding a quality slow-release fertilizer.

Adding just a couple of these pretty fall flowers to your late-season display will give it a boost. Hardier varieties can be planted in the garden now, or save a few for your need-to-get spring list.

Late-Summer Garden Tasks for a Happy Garden

Late-Summer Garden Tasks for a Happy Garden

Sometimes this time of year is referred to as the “dog days of summer”; however, I do not think of it in these terms. Yes, it is hot, many garden flowers are flagging, and there are garden tasks to do, but August is also a month when there is much for us to enjoy in the garden. As I sit on my deck this August morning, I am surrounded by colorful pots of salvia, begonias, lobelia, heliotrope, abutilon, fuchsias, and even a Doris Day floribunda rose bush. But, to enjoy the late-summer garden, it needs daily care.

Groom Tired Flowers

Flagging petunias will appreciate a mid- to late-summer haircut to keep them pretty into fall.

One of my early morning tasks is to remove old flowers and perform some general grooming to keep all my garden plants looking as good as possible. I carry a pair of sharp pruners and snip off any out-of-line branches, poor-looking foliage, or dying flowers. It takes little effort and keeps the garden looking its best. (For more detail, read Teri Keith’s recent article about pruning and deadheading garden perennials and annuals in midsummer.)

Cut Flowers for Bouquets

Cut bouquets of your favorite, long-lasting cut flowers in the garden.

Dahlias are just coming into their prime blooming season and should continue to flower until about the middle of October.  Yesterday, as I was walking my dog, a neighbor was cutting dahlias and gave me a beautiful bouquet. On hot days, dahlia foliage and flowers can quickly wilt in the summer sun, and a top dressing of Black Gold Garden Compost Blend can help alleviate this issue by helping to retain moisture. Cut dahlia flowers early in the day when they look their best and keep them picked to prolong their blooming season. (Click here to read our recent garden article detailing Jessie Keith’s favorite summer cut flowers.)

Feed Container Gardens

Now is the time to fertilize and give containers extra water.

By the time August arrives, many plants in containers that have grown throughout the summer will have root systems that have begun to fill the container. Once roots fill a container, they will begin to circle the wall of the pot resulting in a pot-bound planting. This root mass will quickly become dry, and the plants will wilt from lack of water. I have found that some containers may need watering twice a day if it is hot and especially if there are drying winds. Don’t expect rain to supply the needed moisture as the foliage can be so thick that the water does not penetrate the soil. Water each container at the base of the plants until the water runs out of the bottom of the pot into the saucer or reservoir. August is also a good time to give plants in containers fresh all-purpose fertilizer because many of the original nutrients have leached out.

Prepare the Vegetable Garden for Fall

Late summer is the time to plant cool-season crops, like lettuce.

Some early-season vegetables may be on the decline. Remove them to make space for a fall vegetable garden. Add fresh amendments before planting fall vegetables. Black Gold Natural & Organic Ultra Outdoor Planting Mix is a great vegetable garden amendment that is OMRI Listed for organic gardening and contains mycorrhizae to encourage better growth, naturally.

It depends on the specific area you live in, but here in Oregon’s Willamette Valley, we plant peas can good herbs for the fall garden as well as beets, carrots, chard, lettuce, and kale as well as other brassicas. Now is the perfect time to purchase seeds and get your fall vegetables growing.

“Edit” Your Garden for Fall

Iris and daylilies can be divided in late summer as you “edit” your garden.

August is a good month to think about some garden editing. In my own garden, I occasionally plant plants in the wrong place, or perhaps they have grown larger than I had expected. When moving them to new locations, I make sure to remember where spring bulbs are planted, or I move the bulbs as needed. I also consider the surrounding area and how it might have changed in terms of light and wind. As trees and shrubs grow or are pruned, they may be casting shade on plants that need the sun or providing more sun to an area that was once shady.

If your garden has bearded or Siberian iris, late August is an ideal time to divide them. Often, beds of bearded iris decline in bloom because they are too crowded, while clumps of Siberian iris can quickly become too dense. Diving both about every three years will ensure that they bloom beautifully each spring and don’t overgrow an area.

Give Roses a Boost

Now’s the time to prune off damaged branches, old blooms, and feed your roses for the fall.

Keep roses picked and cut the stems long on hybrid-tea types for the vase. New growth will appear, and the new flowers of fall will be more at eye level where their scent can be best enjoyed. Fertilize roses one last time before spring.

In these troubling times, our gardens, whether large or small, can offer us a hiatus from some of the negative forces around us.  Even a small area on a deck, balcony, or patio can give us some respite from the world in which we live. Enjoy your plants, and realize that they don’t know what is going on around them. Give them water and nurture them, and they will provide you with much pleasure.