When Banning an Invasive Plant Is Bad

Now that the election is past, there is a shortage of contentious discussion, so it seems like a good time to mention a horticulture battle: native plants versus non-native plants. There are rabid supporters in both camps, both with rational arguments.

One of the reasons that this topic moved to the top of my blog priority list is the recent ban on the sale of Elaeagnus, a shrub whose common names include Silver Leaf, Thorny Olive, Silverthorn, Autumn Olive, and Russian Olive (and Ugly Agnes among its detractors). Beginning October 1, 2024, South Carolina banned the sale of Elaeagnus angustifolia, Elaeagnus pungens, and Elaeagnus umbellata. This makes it the second genus with sales banned in SC, after Bradford Pear.

I do not dispute the downsides of growing Autumn Olive in the garden. Birds eat the seeds and spread them into forests and woodlands, where they may displace native shrubs. They can fix nitrogen in poor soils and establish themselves as a monoculture, never a healthy situation. Left unrestrained, they can throw rampant growth and shade out native plants. All negatives, certainly. But in banning all these Elaeagnus, we are ignoring the research and development of non-seeding cultivars underway in a neighboring state. And we are turning a blind eye to Autumn Olive’s ability to stabilize steep slopes with poor soil, where few natives would survive. Demonizing the entire genus makes as much sense as banning ALL Butterfly Bush or Rose of Sharon, even though there are sterile or seedless cultivars available.

There are those who encourage the ban of Nandina. While Nandina berries are toxic to birds that gobble too many of them, there are few other heat- and drought-tolerant plants that will thrive in sun or shade, any soil texture or pH, with no added irrigation. Banning the sale of Nandina ignores the multitude of non-invasive or seedless cultivars: ‘Gulf Stream,’ ‘Flirt,’ ‘Fire Power,’ and ‘Harbour Dwarf,’ to name a few.

Not all natives are innocent. Trumpet Vine (Campsis), Goldenrod (Solidago ), Cattail (Typha latifolia), and Fishpole Bamboo (Phyllostachus aurea) spread like mad and can choke out other valuable plants. Some of our most beautiful plants are not native. I am not willing to remove my Camellias (both C. japonica and C. sasanqua), Bigleaf Mophead Hydrangeas, or Encore™ Azaleas. None of these are native to the United States.

Often, plants that are invasive in one part of the country are fine in another. I was surprised to find Castor Bean (Ricinus communis), Chaste Tree (Vitex agnus-castus), Pachysandra (Pachysandra terminalis), Mock Orange (Philadelphus coronarius), Creeping Jenny (Lysimachia nummularia), and Thunberg Spirea (Spiraea thunbergia) on the Invasive Plant Atlas of the MidSouth, published by the US Geological Survey. To download a complete list, click HERE. I have never experienced an out-of-control spread of any of these. In the case of Pachysandra, I had to plead with the plant to survive and spread.

To quote politicians’ jibber-jabber ad nauseum, “let’s work both sides of the aisle” to make wise choices for our specific areas. Beautiful gardens can contain a mixture of both natives and non-natives. Just make thoughtful selections. There are good choices and bad choices but no inherently evil plants (except for Chameleon Plant, Houttuynia cordata – straight from Hades).

The leaf underside of Elaeagnus pungens. Photo by Bri Weldon used under CC BY 2.0 license.

Storm Surviving Perennials

Many of us in the NC/SC/GA/TN area are in recovery mode from the devastating damage caused by Hurricane Helene. As I write this, Hurricane Milton is getting closer to Florida. In the past, I have written about the Lake Lure Flowering Bridge in Lake Lure, NC. The photos of Lake Lure and neighboring Chimney Rock show heartbreaking damage There will be a long, long recovery.

I’m sure that you have all seen photos of the storm damage, so I won’t belabor the point, but I wanted to share one photo of a house three miles from us that was literally split in half by a toppled tree.

A massive oak tree split my neighbor’s house in half.

My house and barns were undamaged but my woodlands lost many large trees. Just two days after the storm, I sat on my front deck and marveled at the resiliency of nature. Butterflies and hummingbirds worked tirelessly, instinctively aware that cool weather is in the near future. Nearby, pileated woodpeckers complained loudly that their home trees were felled, but then they got busy chiseling new holes. It sounded like a construction crew hammering. A few perennials were unfazed by the thirteen-plus inches of rain that fell. Though many have long passed their peak beauty, Lantana and Cuphea look as good now as they did four weeks ago. So does my white Muhly grass, the focus of today’s blog.

Last year, I installed groupings of Muhlenbergia ‘White Cloud’ and Mexican Salvia. My plan was to highlight the purple and white flowers of the salvia by providing them with an airy white background. Many salvia stems were broken in the recent storm and a few plants were even blown from the ground, but the white Muhly grass looks great.

While many gardeners grow pink Muhly, the white form Muhlenbergia capillaris 'White Cloud' has some advantages over its warmer-toned sister. The white type has a more upright form than the pink. It blooms about two weeks later, so it is a perfect companion to fall-flowering salvia, asters, tall sedums, and chrysanthemums.

White Muhly is cold-hardy in zones 6-9. It will tolerate almost any well-drained soil as long as it is given full sun. To avoid problems, site plants in areas with good air circulation and avoid over fertilization. Spent seed heads look attractive well into winter. Give them a shallow cutback in late winter or early spring, being careful to avoid crown damage.

According to Hoffman Wholesale Nursery, “Muhlenbergia was named after one of the first early-American scientists, Lutheran minister and self-taught botanist, Gotthilf Henry Ernest Muhlenberg (1753-1815). He became interested in botany while hiding from British soldiers during the Revolutionary war.”

Plants grow to three feet tall and three feet wide. They look best when planted as groups rather than as singles. are deer and rabbit resistant. They are native to central and southern US.

This mass planting of Muhlenbergia appears to advantage at the top of a retaining wall.

Cuphea Candy Corn

Lantana

Post storm grouping

Chrysanthemum Sheffield Pink

Blue-Eyed Grass as Feature or Edger

While weeding in a community garden last week, I encountered a plant I had written about several years ago, Blue-Eyed Grass. I have not grown it in my home garden. One of its common names is Bermuda Blue-Eyed Grass. After battling common Bermuda (aka wiregrass) in my lawn and flower beds, I was not about to introduce any plant that shared the name or other characteristics. I’ve been keeping a watchful eye on the specimens in the community garden for two years now, and they appear to be well-mannered. While diminutive in size, their impact is powerful. It’s time to reconsider my initial wariness.

Blue-Eyed Grass is Sisyrinchium angustifolium, pronounced sis-ee-RINK-ee-um an-gus-tee-FOH-lee-um. The species name has changed several times, but the genus Sisyrinchium remains consistent. Blue-Eyed Grass is a semi-evergreen, clump-forming native found across most of the eastern half of the country, in zones 4-9. Plants are undemanding. They grow in any texture soil and partial shade to full sun, preferring a consistently moist soil and average fertility. Rich soil or too much fertilizer results in lush leaf growth and few flowers. Keep mulch away from the base of the plant to avoid root rot.

They can be used singly as a specimen or as an edging. When flowering is complete, trim the spent heads to prevent unwanted spread. Blue-Eyed Grass looks at home in rock gardens, cottage gardens, woodland gardens, and sloped gardens. Bees and butterflies love their pollen and nectar, so they work well in pollinator gardens as well.

Mature clumps of Blue-Eyed Grass can reach up to 16 inches, although 12 inches is more common. The blue flowers appear in spring and summer, and are held above the foliage. Like other members of the Iris family, clumps should be divided every year or two to keep them looking healthy. The cultivar ‘Lucerne’ has larger flowers than unnamed varieties.

Sisyrinchium angustifolium, Blue-Eyed Grass, used as a specimen in a community pocket park.

Easy, Pretty Tatarian Aster

Asters adorn the fall garden with clouds of blue blooms that show to advantage against yellow goldenrod, orange pumpkins, and the warm shades of autumn leaves. The Asteraceae family was one of the largest until those pesky taxonomists got involved. With their penchant for genetic accuracy, they reclassified North American asters into Symphyotrichum, Eurybia, and a number of smaller classes. For an exhaustive (mind-numbing) discussion of Aster’s new family tree, consult the University of Waterloo’s research report by clicking HERE.

Today’s feature plant, Tatarian Aster, was formerly Aster tataricus and is now Crinitaria tatarica (pronounced krin-ih-TAIR-ee-ah tah-tair-IH-ka). Tatarian Aster is a perennial wildflower with soft lavender-blue, star-shaped flowers held in flat-topped groups. The flowers have 7-20 petals each, arranged around a yellow center. Bees, moths, and butterflies love them. They provide a nectar meal for migrating Monarch butterflies.

Tatarian Asters grow in zones 3-9, in any soil type and almost any pH, and require full sun exposure. Plants are resistant to heat and humidity. They may gain heights of up to six feet, but rarely need to be staked unless they are grown in very fertile soil with plentiful moisture. Unless you enjoy staking, take a Tough Love approach to growing this perennial. Plants grown in rich soils with plentiful moisture can spread aggressively.

The height of Tatarian Aster means it is a good back-of-the-border feature. It is especially pretty when grown along the sunny edges of woodlands, paired with Miscanthus, Muhlenbergia, or other grasses. Deadheading spent blooms will lead to a lengthy flowering season, from late summer all the way to freezing temperatures. In winter, cut the dead foliage back to ground level.

Muhly Grass for Autumn Color

Autumn colors are orange, red, yellow, rust…and pink? Across the southeast, Pink Muhly Grass (Muhlenbergia capillaris, pronounced mew-len-BERG-ee-ah or mew-len-BER-jee-uh) is reaching its peak. We do not usually think of grass as a flowering plant, but there is no mistaking the decorative value of pink Muhly. Its feathery plumes float like clouds of pink cotton candy. A white-flowered form is available also but is harder to find than the pink variety. White varieties bloom a little later than pink forms.

 Mulhy is easy to grow in full sun, zones 6-9. Native to North America, it will grow in sandy, rocky, or clay soil. Avoid constantly wet soils. It is not troubled by insects or diseases, and is highly resistant to deer damage. Plants grow up to four feet tall and  three feet wide. Established plants are heat and drought tolerant. The narrow leaves sway gracefully in breezes. Flowering begins in autumn and is followed by attractive seed heads that persist through winter, providing food for birds. The purplish-pink form ages to a creamy tan color and the white form ages to an attractive gray.

 A standalone plant is attractive, but mass plantings of Muhly are gorgeous. Two pairings that are particularly attractive: Pink Muhly with purple-leaf Loropetalum,  or White Muhly paired with purple-flowered Mexican Salvia (Salvia leucanthemum).

 Plants may need to be divided every three years or so to avoid dieback in the centers. Give clumps a cleanup cut in late winter or early spring, before new growth starts, but do not cut so short that the crown is damaged. While some other grasses may become invasive, Muhly is well behaved and makes a perfect addition to the low maintenance garden.

Pink Muhly Grass used as an edging

Blooms look like cotton candy

Rhododendron Family - Part 3: Native Azaleas

Native Azaleas are less in-your-face showy than other members of the Rhododendron family, but they are my favorite. They are native to the US, unlike the popular Popsicle-colored, evergreen Asian Azaleas that are found in many southern landscape plantings.

The Natives are taller and more open than their Asian counterparts. They are deciduous, losing every leaf in winter. In spring, the flowers appear before leaves.  The vivid yellow, orange, red or pink blooms glow like torches in the woodland areas where they occur naturally. Given the proper soil (moist, acidic) and light (morning sun, afternoon shade), they perform well in home gardens also. When not in bloom, they fade into obscurity. They look best when incorporated into a natural area rather than jammed against a house foundation. A mature plant may reach 10 to 15 feet, so site accordingly.

There are more than a dozen species of native Azaleas. Many are fragrant. Clemson University has compiled a useful fact sheet, listing species, colors and bloom times. Find a link to their information by clicking here.

According to Alabama and Auburn University Extensions, there are several hybrid groups that are more heat tolerant than most: Aromi hybrids, Auburn series, Confederate series, Sommerville series, Strickland Azaleas, and Clarence Towe’s selections. My friends in the nursery world recommend ‘Admiral Semmes,’ a yellow-flowered shrub in the Confederate series as a strong performer. I cannot distinguish a Piedmont Azalea from a Pinxter Azalea. Both have pale pink flowers with protruding stamens that are beyond gorgeous. Bees, butterflies, and hummingbirds flock to all the native Azaleas. Unfortunately, they are also a deer favorite.

Plants may be propagated from seed or root cuttings. I have experienced failures with both, so will be content to purchase mine from a garden center. Native Azalea is the state wildflower of Georgia.

This ‘Admiral Semmes’ (a Confederate hybrid) is in full bloom, with flower trusses that would rival its showier cousins, the Rhodies.

Pinxter Azalea. Photo by Jerry King, Reidville, SC.

Close view of an ‘Admiral Semmes;’ flower.

The bud of a Flame Azalea inspired its name, since they look a bit like candle flames. This photo Image by Rebecca Matthews from Pixabay

Delicate Trout Lily for Earliest Spring Bloom

In late winter, stumbling across a blooming patch of Trout Lily is an unexpected bonus,  like discovering a $20 bill in the pocket of a rarely-worn jacket. Erythronium americanum, Trout Lily, is sometimes called the Yellow Dogtooth Violet or Adder’s Tongue. It would take an active imagination to conjure the delicate yellow flowers with brown or bronze reverse into a fish, canine teeth, or a snake’s tongue.

This lovely ephemeral is native to the eastern US. “Ephemeral” means “fleeting,” which is exactly how this plant behaves. It blooms in early spring before tree leaves emerge, about the same time as Crocus. Soon after flowering, the plant produces seeds and then withers away. The seeds will eventually develop into corms, a type of bulb. They are sold as corms, not seeds. Plant in fall for best results. Most corms prefer shallow planting, but Trout Lily likes a deep hole (five inches) which seems unusual for such a small bulb. The seeds are spread around by ants.

Plants thrive in moist, shady woodlands with acidic soils. It takes a year or two for juvenile plants to start blooming. Juveniles are easy to spot since they only produce a single leaf rather than the paired leaves of mature specimens. Plants reach a mere six inches in height, with the bloom stems slightly taller. Older plants may stop flowering if the bulbs become too congested. In this case, lift and divide just as the plants begin to go dormant.

Trout Lily leaves have a mottled appearance. Flower petals curl back toward the stem, described by botanists as recurving. Blooms are one- to three-inches in diameter. Flowers contain six yellow stamens and reddish-brown anthers. There is a less common white form, E. albidum, whose white flower petals are flushed with lavender on the reverse side. Adder’s Tongue, E. propullans, is  a pink-flower form found only in Minnesota. Strangely, it bears a small bulblet halfway up the stem.

Trout Lily looks delicate but it is quite sturdy, making its appearance early in the year when frosts and freezes are still common. The flowers attract bees. The corms, unfortunately, are tasty to small forest critters although deer usually leave them alone. Protect them with a circle fence of buried fine-mesh wire or a gravel moat. Since I have both cats and dogs, I researched their toxicity. One source said that the bulbs were edible, with a cucumber-like taste. Another said that the bulbs were an emetic (makes one vomit). No further testing on my part! I opted for the protection of the wire mesh to prevent my pets from tasting.

The bronze backs of the Trout Lily petals are evident in this photo. Note the mottled leaves.

Trout Lily bloom detail