The Mpemba Effect

The southeastern US typically has a few bitter cold days each winter, but our cold snaps rarely continue more than a day or two. The recent winter chill has been long-lasting and brutal. Even South Carolina’s coastal areas saw snowflakes this week, while piedmont and foothills are shivering in the “feels like” teens, even in daytime. Like many other gardeners, I am worried about the impact on my evergreen trees and shrubs. Tree roots are unable to absorb enough to replace moisture that has been stripped from conifer needles by cold winds. Dried out trees and shrubs may weaken, discolor, or even die. The Arbor Day Foundation has an excellent article on when and how to water trees in the winter. The short version: water trees once or twice per month when daytime temperatures are 40F and above. Click HERE to read the full article. Water evergreen containers weekly.

Our senior dogs are content to snooze indoors in their toasty beds, with their food and water bowls nearby. Our outdoor cats have heated cathouses and cat-door access to heated and insulated barns. We are doing our part to support wildlife, keeping birdfeeders full and fresh water available. While we have two creeks running through our woodlands, we also have water bowls all around the property. These are visited by raccoons, squirrels, opossums, skunks, foxes, coyotes, and deer.

Birds of all types cluster around our birdbaths. The birdbaths require regular attention because they are too distant from electricity sources to use water heaters. I assumed that filling these containers with warm or hot water would delay their freezing, but I have learned that warm water will actually freeze faster than tepid water. (Trigger warning: science speak to follow.) This counterintuitive phenomenon is called the Mpemba effect (pronounced em-PEM-ba).

Aristotle first hypothesized this phenomenon, but it was not named until 1963 when tested by a Tanzanian physics student named Erasto Mpemba. Without getting too technical, I can relate that hot water and cold water reach thermal equilibrium at different rates. When two samples of water are cooled, the hotter sample freezes (reaches equilibrium) first. Equilibrium exists when energy is neither flowing in or out of a substance. Water that has formed into ice has a stable volume.

Allow me to quote from an article from the HowStuffWorks website: “For water to freeze and stay frozen, individual water particles have to reach equilibrium. If too much energy surges through nonequilibrium water, it will fluctuate between solid and liquid (at low temperatures) or liquid and gas (at higher temperatures). The sooner that water particles reach equilibrium at low energy levels, the sooner they can freeze…When a vessel of water is submerged in a freezing environment, different parts of the water reach equilibrium at different times. Water around the outskirts of the vessel gets colder faster, which means that it may freeze while water in the middle of the vessel stays liquid. And when you specifically place a vessel of hot water in a freezer… it is also releasing steam from the top of the vessel, and this decreases the total volume of water that needs to freeze. Furthermore, cold water (or even room temperature water) often develops a layer of frost on its surface as part of the freezing process. Ironically, this frost temporarily insulates the water (kind of like how an ice igloo insulates its inhabitants against cold air), which can slow down the overall freezing process. Hot water, at least in the early stages, blocks the formation of frost, which allows cold air to penetrate deeper into the vessel.”

There has been ongoing disagreements and debate among scientists about the Mpemba effect. All sorts of factors come into play: contaminants in the water, size of the vessel, volume of the water, others. While undeniably brilliant, Aristotle and Descartes did not have access to the same laboratories that are available today. Which is why it is significant that the theory was successfully tested in modern times by Zhiyue Lu of the University of North Carolina and Oren Raz of the Weizmann Institute of Science in Israel. Their results were reported in Quanta magazine. Another test, conducted in 2020 by John Bechhoefer and Avinash Kumar, supported the earlier results and was printed in Nature magazine.

While it does not seem logical that my birdbaths will freeze faster when filled with hot water than with cold, I will bow to the professional physicists and change my ways. Our wildlife cannot speak, but I know they appreciate their water sources. And as soon as daytime temperatures become warmer, I will be out there watering my arborvitae, hemlocks, boxwoods, and euonymus while I long for spring’s arrival.

Flamboyant Pileated Woodpeckers

Our rural location in upstate South Carolina is a bird mecca. We host a variety of bird species, large to small. One of my favorites is the pileated woodpecker, which are common across southeastern forests. Last summer, I tried repeatedly to capture a photo of these beautiful birds. We have at least six living in the woods near our home. They became accustomed to my presence in the front gardens, and would swirl and swoop around as if they were showing off their pretty black, white, and red plumage. Every time I popped the lens cover off the camera, however, they disappeared. When the lens cover went back into place, they would reappear. It was almost as if they were messing with me. I finally gave up, contented to see them at a distance, hear their distinctive calls, and witness their impressive excavation skills.

The first time I saw one of their squarish excavations, I did not realize what I was seeing. Later, I found that the tree was inhabited by large black ants, a favorite snack of the pileated woodpecker. Still later, I witnessed one going after the insects inside the bark of a tree stump near the driveway. The noise alone was impressive, but the shower of wood debris sent all directions was awesome.

Pileated woodpecker are big birds, almost as large as crows. Their heads are topped by neat red crests that make them easily distinguishable. The word pileated means capped. You can see large patches of white on their wings when they fly. The head crest on juveniles is smaller and less pointed, almost like a bird version of mohawk haircut.

As long as dead trees (“snags”) in our woodlands are not endangering buildings, driveways, or walking paths, we allow them to stand. These snags offer an ideal bird home. Woodpeckers seem to prefer tall trees over shorter ones. They raise one brood in a tree cavity, then abandon it and create a new cavity for the next brood. These excavated holes are used by other birds and small mammals. An average pileated brood consists of four eggs. Hatchlings fledge in about a month.

Pileated woodpeckers mate for life, but males and their females roost in separate cavities at night, even if they use the same tree. They are primarily insect-eaters but may also visit feeders, especially if suet is offered. They also eat fruits, nut, berries, and beetle grubs.

In late November, I misidentified a small bird that was visiting my prized Styrax japonica tree. I thought it was a juvenile pileated woodpecker, but when I approached, I realized that it was a redbellied woodpecker systematically destroying the tree’s bark. I kept shooing it away but this fella was not to be deterred. I eventually wrapped the tree trunk in hardware cloth, which he ignored. I then swaddled the entire tree in a garden mesh fabric. It looked awful but I was willing to do what had to be done to avoid the trunk being completely girdled and the tree killed. Aside: why, oh why, is a redbellied woodpecker so named, when it has a red head but not a red belly?

Pileated woodpeckers do not migrate. And I am happy to report that their populations are growing, a remarkable feat considering the housing growth in America taking over woodlands. Banded birds have been studied for their longevity. They have a lifespan of 12 years or so.

A male pileated woodpecker. The cheek stripe on a female is black instead of red.

Expanding The Gardeners' Vocabulary

I added a new word to my gardening vocabulary this week: thermotropism. In simple words, this is a plant’s reaction to temperature changes. Rhododendron exhibits one of the most obvious reactions to cold weather. When the weather turns frigid, Rhododendron leaves curl inward. It may look like the plant is suffering from drought, but instead it is reducing the surface area exposed to cold to keep internal moisture from evaporating.

While I was researching thermotropism, I discovered an entire family of -isms in the horticulture world. Phototropism is when a plant moves in reaction to light (sun). I’m sure you have seen in your own gardens how sunflowers turn their heads to the east to catch the morning sun, then slowly turn toward the west as afternoon arrives. Foxgloves and daffodils do the same.

Thigmotropism is when a plant encounters a solid surface and reacts to it – like a morning glory curling around a trellis. A reaction to the presence of chemicals is chemotropism. Think of the way roots move towards areas of higher soil fertility. A plant’s reaction to gravity is called geotropism or gravitropism. Movement in search of water is hydrotropism. And some plants react to touch. The tickle of insect legs will cause a Venus Flytrap to snap closed around its next meal.

The southeast is predicted to experience a serious winter storm later this week, the first measurable snowfall in my town since 2022. It might be an insignificant event in the opinion of my friends that moved from Michigan, Minneapolis, and South Dakota. For this SC native, anything more than an inch of snowfall can rightfully be called a blizzard. So, I’m going to practice thermotropism, and wrap myself into a down duvet like a human taco. Friends, stay safe and warm!

Thirsty? No - COLD! This Rhododendron has curled its leaves as self-protection..

Photo By Nicholas A. Tonelli - Flickr: Nature's Thermometers, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=24186333

Make A Woodland Walk Part of Your New Year's Tradition

Happy New Year. I hope that 2025 brings you happiness, good health, and gardening prosperity. Here in the deep south, we love our traditions and traditional holiday foods. How else could one explain the annual December appearance of green bean casseroles, sweet potato casseroles, and the shimmering blob of cranberry gelatin still bearing the marks of the metal can from whence it came? Many of us celebrate the onset of the new year with meals including collard greens, black-eyed peas, and cornbread.

According to folklore, eating greens (collards, turnip greens, cabbage, or my new favorite, roasted brussels sprouts) is supposed to ensure that one has plentiful green paper currency in the coming year. Black-eyed peas represent coins. Cornbread is supposed to symbolize gold. Newly landed European immigrants adopted cornbread from Native Americans, although I wonder how it compared to today’s version. Jiffy mix, anyone? My husband is a cornbread purist, insisting on no sugar or wheat flour, and mandating that buttermilk is a required component of the mix. I can forgo the sugar, but like to add chopped jalapenos for extra flavor.

Commonly, these traditional new year foods are seasoned with some type of pork – bacon, fatback, cracklings, various and sundry porcine parts. My husband grew up having a couple of pigs as part of the farm livestock. I was a city girl, so had no experience with the animals. I understand that pigs are intelligent, affectionate, and trainable, so they can almost be treated like 600-pound dogs. The swine circulatory system is similar to that of humans. They are often a source for human heart valve replacements and I saw a recent new report about a woman who had received a porcine kidney transplant. Over the weekend, I saw a large (at least 400 pounds) pig free-ranging on fallen acorns not more than fifty feet from a state highway. I hoped that the owner would soon corral him/her, but have seen multiple neighborhood reports that indicate this free spirit is still on the loose.

My preferred calendar-change kick-off includes a good book, a pot of coffee, a dog warming my feet, and at least one cat in my lap. The next two months are typically gray, cold, and gloomy. Some people suffer from a disruption of their circadian rhythms, and experience a form of depression called SAD, Seasonal Affective Disorder. If you are similarly troubled, please seek professional advice. Or, take my non-professional but well-intentioned recommendation to GET OUTSIDE. A thirty-minute walk outdoors always lifts my mood, even on the grayest of days. A walk is even more regenerative if it includes the companionship of a friend and takes you through a park or wooded area.

Enjoy the lull right now, because February ushers in the season for dormant pruning. More about that later. Right now, resolve to greet each new day with a positive attitude, confident in the knowledge that spring will arrive again.

Black eyed peans and pork, a staple of the New Year’s Day menu.

Photo by jeffrey w, CC BY 2.0, via Wikimedia Commons

Ixora for Color Impact

A few months ago, I was hosting a garden club meeting and wanted a container plant to add seasonal color near the entrance door. I visited the garden center of a home improvement store, intending to purchase a Croton (beautiful waxy leaves but not cold hardy in my area) or Chrysanthemum (predictable, boring). Instead, I spotted a plant covered with clusters of gorgeous orange flowers. Though I did not know the name, I instantly recognized it as the same beauty that I had encountered and admired many years ago. Back then, it was in a large patio container of a home on garden tour. The hostess told me the name, which I promptly forgot, and said that it was tender but she loved it so much that her husband used a hand truck to haul it into their heated basement each winter. The one at the home improvement store was labeled, Ixora.

I was feeling pleased with myself when Ixora rode home in my backseat. A little research revealed that this was Ixora coccinea, pronounced ik-ZOR-ah kock-SIN-ee-uh. Common names are Jungle Flame, Flame of the Woods, and Jungle Geranium. The genus name seems to fit the exotic appearance of the plant, so mine is labeled Ixora.

Ixora is native to Asia. It is evergreen and common in Florida. Unfortunately, it is only cold hardy as far north as zone 10, and will suffer under 50 degrees. While mine is orange, Ixora coccinea is also available in yellow, pink, and red. Ixora takes full sun, regular irrigation, acidic soil, and monthly applications of fertilizer. The mature height can be over 5 feet, but it is usually kept smaller by an annual pruning in early spring. Avoid more frequent cutbacks to avoid removing flower buds  Plants flower almost continuously, late spring to fall.

I became less diligent about watering my potted specimen as cool weather approached. New buds stopped appearing, and the shiny leaves started to look dull and crispy. I moved it into the greenhouse with the intent of taking a cutting or two. Six weeks of light, warmth, and regular water in the greenhouse, and my Ixora is blooming as beautifully as it was the day it came home with me. I pruned all branches with the intent of keeping the plant small and dense. I treated the trimmings with rooting hormone and stuck them into damp vermiculite. They rooted quickly, and I have already moved nine plants to individual containers for growing on. In spring, I will select one to preserve as a “mother” plant, and place the rest of them in the ground in my courtyard garden, treating them as annuals. Of course, this assumes that the cuttings will survive in the greenhouse from now until mid-April. Grown indoors, Ixora is prone to mealybugs, thrips, and scale, and probably whitefly as well. I’ll tend them diligently, because OH, what a payback!
Whether you choose to keep yours as a houseplant or overwinter it in a greenhouse, reduce watering and fertilizing during the dormant period.

This Ixora was looking pathetic as fall approached. A few weeks of sun, heat, and water in the greenhouse and it has burst into flower again.

Cleyera Is An Improved Hedge Choice

As I assembled holiday arrangements today, I fondly remembered a hedging plant from my garden of many years ago, Red-Tip Photinia. In the early 1980’s, many southeastern gardens contained hedges of Photinia x fraseri, widely known as Red Tip after the reddish coloration of new growth. Red Tip fell victim to a fungal leaf spot that virtually wiped it out. Disease problems are exacerbated when large numbers of the same plants are located in a narrow area, called a monoculture.

Fortunately for us gardeners, a worthy replacement to Red Tip has surfaced in form of Cleyera, or Ternstoemia gymnanthera (tern-STROE-mee-uh jim-NANTH-er-uh). In some ways, Cleyera is better than Red Tip. It prefers neutral to acidic soil (no lime required). It is slow-growing with a mature height of 8-10 feet, which means it is low-maintenance. Consider it as a replacement for Leyland Cypress. It has a loose, open habit but it can be kept shorter and made denser by limited pinching or light pruning once per year. For faster growing specimens, look for the cultivar ‘Contherann.’

Cleyera prefers a bit of shade to prevent its leaves from scorching. In spring, Cleyera has small white flowers, followed by green berries that turn red in fall. Neither flowers nor berries will wow the observer. Instead, enjoy attractive glossy, bronzy-red new growth in spring, dark green summer leaves, and slightly bronzed fall leaves. While it will never be the star plant in the garden, it is an evergreen that makes a great privacy hedge choice for partly-sunny or partly-shady areas.

Cleyera is cold-hardy in zones 7-9. It tolerates a wide range of soil types. Avoid planting Cleyera in locations that are constantly wet.

Mid-summer leaves of Cleyera. Photo by Jim Robbins CC BY-NC-ND 4.0

New growth of Cleyera. Photo by Krzysztof Ziarnek, Kenraiz CC BY-SA 4.0

A mature specimen of Cleyera, Ternstroemia gymnathera ‘Le Ann’. Photo by Jim Robbins CC BY-NC-ND 4.0

Holiday Greenery for Yew-All

My favorite fresh greenery for holiday decorating is Yew or its close associates. I love the look and scent of fir, pine, and eastern red cedar (which is really a member of the Juniperus genus, not Cedrus, but why quibble over the name?). My garden SC is too warm for growing fir, so any branches I acquire have been shipped from a cooler zone, meaning they are not freshly cut. Pines are abundant throughout our woodlands, and the scent is evocative of Christmas celebrations, but the cut ends of branches exude a sticky sap that is difficult to remove. Eastern red cedar also has a wonderful fragrance. Some trees are adorned with powdery blue berries. It does not take long for berries to shed and cut cedar to dry out. Then it becomes brittle and scratchy, shedding profusely. This is why Yew or Plum Yew is my seasonal greenery of choice.

The “real” Yew is in the Taxus genus. It has short, dark green needles that are easy to use in wreaths and indoor holiday arrangements. It is not as heat tolerant as the Cephalotaxus genus, commonly called Plum Yew. Plum Yew needles are longer than Taxus. It is available in low/prostrate, medium/shrubby or tall/skinny forms. ‘Prostrata’ is a short, spreading evergreen shrub for shade. It reaches two feet in height but spreads up to six feet wide.  It makes a perfect foundation plant for shady areas under low windows or the north side of a home.  ‘Duke Gardens’ is taller but narrower, reaching up to five feet in height but maybe six feet wide. Its branches are angled upward, typically described as vase shaped. I was today-years-old when I learned that the name is Duke Gardens and not Duke’s Garden. Both the prostrate form and the vase-shape form require partial shade to full shade. Their needles are held in almost flat planes, though they tend to angle upward when grown in more sun. The tall, narrow form, Cepahalotaxus harringtonia ‘Fastigiata,’ will take more light that the last two, although it still prefers to be shielded from direct afternoon sun. Its needles spiral around the stem. All forms are slow growing, which means low-maintenance. In my cut flower arrangements, ‘Fastigiata’ makes a great filler and will stay fresh looking and needles will stay soft for several weeks as long as its stems are in water. 

Once they are established, Plum Yews are heat-tolerant and moderately drought-tolerant. Deer normally pass them by. 

A Plum Yew lookalike is Podocarpus, commonly called Japanese Yew. Its needles are longer than Plum Yew. In the landscape, it will take a lot more sun than Plum Yew but it is not as cold-tolerant and it will not tolerate wet soils. Podocarpus can be sheared into hedges or pruned into topiary.

The new growth on this Cephalotaxus harringtonia is a bright green. The small size of the spring growth spurt tells the gardener that this is a slow growing, low maintenance plant.

This fastigiate Plum Yew was in an area of my garden that received morning sun. To compensate, I gave it a little water during the hottest months. This is a mature specimen, ten feet tall and five feet wide.

These prostrate Plum Yews are low to the ground. Here they are used to edge a path. They would be idea under low windows on the shady side of a home.

Chindo Viburnum for Privacy Hedge

When cold weather arrives, I retreat into my shell (down vest) like a threatened turtle. There isn’t much to gladden the heart of this heat-loving gardener. Deciduous plants have dropped their leaves, perennials have passed into dormancy, and annual flowers are long gone. The refreshing appearance of evergreen trees and shrubs make the landscape tolerable. Needled evergreens can be damaged by ice. Limbs of broadleaf evergreens like Magnolia grandiflora break under snow loads. Harsh winds punish palms and conifers. Let me recommend an evergreen that seems to tolerate wind, ice, and snow without damage: Viburnum awabuki ‘Chindo.’

Before I met ‘Chindo,’ I thought of all Viburnums as smallish, deciduous shrubs. A few are known for fragrant flowers or colorful fruit. Others have especially nice fall color. The Chinese Snowball Bush is popular for its large, round white flowers in spring, resembling white mophead Hydrangea flowers.

Chindo Viburnum is an evergreen, low-maintenance shrub that will reach heights up to 20 feet and widths up to 15 feet. Plants can be kept smaller with annual pruning. Somewhat irregular in youth, Chindo matures to a pyramidal shape. It is cold hardy in zones 7b-9b. It will grow in a wide range of soil types and acidity. Chindo prefers part shade to full sun. It looks best when shaded from direct sun at the hottest part of the day. Established plants are moderately drought resistant. The thick, dark green leaves are so shiny they look polished. Plants grow fast – one to two feet per year, making it a good choice for blocking unsavory views.

All resources say that Chindo, introduced by J.C.Raulston, is known for its heavy set of red fruit clusters that follow white flowers which appear in early summer. I had a grouping of four plants, three of which were obtained as rooted cuttings from the fourth. I did not experience heavy berry set. In fact, I don’t recall any flowering. This probably means that my plants needed an outside pollinator instead of same-plant clones, and perhaps that I grew them in too shady an area. Even without flowers or berries, it is on my favorites list for its healthy appearance and low maintenance needs. Bonus: Chindo is rarely browsed by deer.

Select Chindo Viburnum for a privacy hedge, as an alternative to Magnolia, Tea Olive, Holly, or Arborvitae.

A bit gawky in youth, shown here, this Chindo Viburnum matured to a lovely pyramidal shape.

Time Change Woes

We changed from Daylight Saving Time to Standard Time three weeks ago. I am still having trouble adjusting. As I sat at the computer last night, ready to research a plant for this blog, my eyes drifted over to the window. Dark, cool, rainy. It must be approaching 10pm, I reasoned. A glance at the clock said it was just a few minutes after 7pm. How is that possible? Instead of delving into horticultural mysteries, I decided to investigate the background of Daylight Saving Time (“DST”).

First, notice that it is Daylight Saving Time, not Savings. Even though Benjamin Franklin is thought to be the originating party, time changes were suggested by George Washington back in 1784 as a means of conserving candlewax. Instead, he suggested that sleeping residents could be roused by the sound of church bells or even cannon fire. This seems absurd now, but that was a different time. His suggestion went nowhere. In 1916, Germany established DST as a way to conserve fuel during World War I. The US followed for seven months before reverting to Standard Time. DST was enacted again by President Franklin Roosevelt in February 1942. This change was for all year, and it was labeled “War Time” (WWII).

In 1945, Congress decided to allow states to make their own decisions about keeping DST or reverting to Standard Time. The result was chaos. Train schedules were impossible to establish without nation-wide consistency. Interstate travel and trade were confused. Neighboring states might be the same, or might not.

Beginning in 1966, our nation’s clocks were reset on the first Sunday of April and the last Sunday of November. In 2007, the reset changed to the second Sunday in March and the first Sunday in November. This alteration was part of the Energy Policy Act of 2005, signed by then-President Bush as part of a larger plan to reduce fossil fuel usage and improve air quality.

All states now follow DST except Arizona and Hawai’i. The change pleases golfers and shop owners, allowing for more people to be out playing and shopping before the onset of darkness. Farmers, on the other hand, want to get started early and say that it confuses their animals. I’ve never seen cattle wearing watches or consulting their phones, so I assume that the displeasure is with feeding times. [If you are a farmer who is unhappy with the change, please feel free to enlighten me.] About 70 countries follow the change, while India, China, Japan, and most African countries do not.

Time changes disrupt our bodies’ natural rhythms, which can manifest itself with increased car accidents, job site injuries, short tempers, and even heart attacks. I am one of those who prefer we pick one or the other, and remain with it instead of the twice-yearly change. I don’t think I am in the minority, since 19 states have requested that DST become permanent. In response, Congress proposed the Sunshine Protection Act of 2023. It died before passage, and was not resurrected in 2024. Perhaps we will see a change in the future.

And I finally learned why the drop-an-hour/add-an-hour change happens at 2am instead of some other time. In 1966, there were no Amtrak trains leaving New York City at 2am, so this was the least disruptive choice and had the lowest impact on travelers.

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.

Great Plant with Identity Issues

I have found the perfect groundcover for sloped garden locations with poor clay soil and no irrigation.

Mezoo is a succulent, trailing annual plant that typically grows to six inches tall or less. In fertile soil and with a little irrigation in dry periods, it may spread to six feet wide. It has fleshy leaves and small flowers that are a bright red or pink color. The succulent stems can be brittle, so if any repositioning is desired, it should be done when the plant is young.

Mezoo will thrive in a wide range of soil types. It is tolerant of both full sun and partial shade. Its drought tolerance makes it a great choice for xeric gardens. Mezoo is a versatile plant that can be used as a ground cover, as a border plant, in hanging baskets, or as a container plant.

Mezoo is low maintenance, susceptible to few pests or diseases, and requires no pruning or deadheading. Mealybugs and spider mites can occasionally be a problem. Mezzo turns to mush with the first hard freeze but established plants will tolerate a light frost. It will not withstand foot traffic.

This is one of those rare instances when I identify a plant only by a common name. I have seen it offered in nurseries as Baby Sunrose, Heartleaf Ice Plant, and Livingstone Daisy. In reference materials, it is listed as Aptenia cordifolia, Dorotheanthus bellidiformus, and most recently, Mesembryanthemum cordifolium 'Variegata'. I may be confused as to the correct binomial identity, but there is no confusion over its beauty and its ability to bring beauty to a difficult planting site.

Mezoo is easily propagated from stem cuttings. My current collection was started from a single plant purchased several years ago. I have already started cuttings for next year to overwinter in my greenhouse. The variegated edge to its leaves means it will brighten a dark area and draw attention to the shrubs it surrounds.

A closeup view of Mezoo’s flowers.

Mezoo in a hanging basket

Photo taken 11/4/2024, after a four week period without rain. This bed is located at the top of a slope. The fleshy leaves of Mezoo contrast nicely with the spreading Yew and does not war with the adjacent variegated Ajuga.

Climbing Hydrangea to Clothe a Tree Trunk

As a result of Hurricane Helene, I have several trees that are missing their tops – bare, limbless trunks a foot or more across, reaching ten feet or more into the air. Because our property is home to a large number of pileated woodpeckers, we do not remove “snags” unless they actively endanger buildings or prized plants. The woodpeckers were distressed by the storm-caused loss of their homes but have quickly adapted. They hammer away to create new cavities. Wood chips piled around tree bases make it easy to detect their new homes. I wanted to plant vines to soften the current stark appearance of the trunks. I considered trumpet vine, cross vine, Confederate jasmine, honeysuckle, clematis, and settled on Climbing Hydrangea, Hydrangea anomala (pronounced hy-DRAN-jee-ah ah-NOM-uh-luh), formerly known as Hydrangea anomala ssp. petiolaris.

Climbing Hydrangea will grow in part sun to full shade, in almost any type of soil. It climbs by twining and also sprouts little sucker feet to adhere to its host. It has white lacecap flowers in summer, attractive green foliage in summer, yellow fall color, and exfoliating bark in winter, meaning it is attractive year-round. Plants are hardy in zones 4-8. They do not get heavy and do not strangle trees. Mature vines are drought resistant.

While Climbing Hydrangea can reach heights up to 80 feet, it is easily restrained to a manageable size. It can also be allowed to grow standalone as a shrub, but may appear unkempt. The vine is slow to establish a good root system and stems grow slowly the first few years. It may take three years or more to produce begin producing blooms. Unlike some hydrangeas, Climbing Hydrangea flowers do not change color according to the soil’s acid level. All flowers are ivory, up to eight inches across, with the centers being small and fertile and the surrounding perimeter being showy and non-fertile.

Climbing Hydrangea can be confused with another vine with similar flower structure, False Hydrangea Vine (Schizophragma hydrangeoides). False Hydrangea flowers may have tints of pink, rose, blue, or purple, and the flower structure is a bit different, with the infertile flowers being larger, and triangular or heart-shaped. Flowers of Climbing Hydrangeas have four petals, while False Hydrangea has a single, heart-shaped sepal.

Both vines are deer and rabbit resistant, but foliage may be damaged by Japanese beetles.

This tiny Climbing Hydrangea will soon adhere and eventually cover the adjacent dead tree trunk with beautiful leaves. It will be a few years before flowers appear.

This hydrangea-covered tree trunk offers wonderful contrast to its bare-barked neighbors.

Helianthus for Sunny Yellow Fall Flowers

While every other perennial plant is winding down at the end of the summer gardening season, the golden heads of Helianthus are approaching peak show. You will notice that I included the genus but not the species. That is because I cannot tell one species from another. What I can tell you is that I spotted this lovely fall-flowering yellow daisy last autumn in a ditch in front of a house with prominently displayed No Trespassing signs. I jumped from the car, snipped one stem of spent flowers, and zoomed down the street before the owners could lock and load.

I stripped the seeds from those dried flowers and started growing them in my laundry room. (This was before the greenhouse arrived.) I had a couple of small plants to set out in spring. They have repaid my care by throwing a dozen lovely yellow flowers per plant. These are hardy perennials for zones 6-9, so I expect the show to improve next year and every year thereafter.

Helianthus, commonly called Swamp Sunflower or Narrow-Leaf Sunflower, is a native that attracts songbirds and butterflies. It has rough, narrow leaves and thin stems that can be damaged by winds or weighted down by its numerous flowers. It is a food source for several butterfly larvae species. Plants are moderately deer resistant.

Perennial species of Helianthus, pronounced hee-lee-AN-thus, share common cultural needs. They flower best in full sun but will tolerate partial sun. They want acidic soil. Plants will get quite tall – to ten feet in fertile soil and sufficient moisture. That is too tall to fit into most garden borders. This too-tall problem can be remedied by pinching plants back several times in spring and early summer to encourage branching and reduce their height. Don’t pinch after mid-summer to avoid removing flower buds.

Allow spent flowers to remain on stems to reseed naturally and your fall garden will soon feature these happy yellow flowers, perfect for inclusion in seasonal flower arrangements.

These are two of the seedlings I started from seed. I will not deadhead them. Instead, I will allow the fallen seeds to start new plants, resulting in a fuller planting in coming years. The bumblebees LOVE these flowers.

Do Not Prune Now

Step away from the pruners. Now. I mean it. This is NOT the time to trim shrubs in the garden. Aside from removing dead or damaged branches, which should be done as soon as they become apparent, leave the cutbacks and neatening until deep winter. For most of us, that means January or February.

Why this moratorium on pruning? Despite the fact that the southeast is in the midst of a period of cool weather, we will likely experience another warm up before real cold arrives. Southeast gardeners joke about this initial cool period being “false fall.” Shrubs that are pruned now will respond with a new flush of growth. This tender new growth is prone to damage when freezing temperatures begin to occur nightly. In some cases, plants wear unsightly shriveled or blackened leaves through winter and into the following spring. In other cases, specifically older cultivars of hydrangeas and azaleas, a fall pruning will result in the absence of spring flowers. Even hydrangeas that are rebloomers (“remontant”) will benefit from pruning restraint until spring arrives. At that time, dead stems are detectable and can be removed without impacting future flowers.

When it comes to fall garden cleanup, people fall into two camps. One group prefers to remove dead annuals, prune back perennials, and add mulch to act as a blanket against temperature extremes and wind erosion. The other group delays cleanup until late winter or early spring, allowing stems to harbor overwintering good insects, provide food and cover for birds, and protect against cold damage. I play both angles. I remove annuals and dead peony foliage, and cut some perennials (rudbeckia, shasta daisy) down to their basal foliage. I leave Lantana and Artemisia alone, waiting for new spring growth to commence before trimming.

Leaves are another controversy. In many subdivisions, I see numerous leaf-filled plastic bags awaiting roadside pickup. I use an opposite approach. I use a leaf-blower to blow leaves out of my flower beds and shrubs onto the grass. Then I cut over the turf with a bagging mower. I empty those leaves, now cut into fine pieces, back into the beds where they fell. They serve as a free insulation blanket to protect plants. The reduced size means they break down quickly instead of sticking together in an impermeable slime layer. Removing leaves from the lawn gives a neat appearance for warm season grasses like Zoysia or Bermuda (dormant in winter) and prevents dead spots in cool season lawns (Fescue) where sun and rain could not percolate down. Rather than adding an excessive layer of chopped leaves to beds and borders, I add any extras to a compost pile where they develop into the precious soil amendment known as “leaf mold” for distribution in the spring.

While cold weather and short days reduce our hours in the garden, it provides time to sharpen shears and hand pruners, and perform maintenance on lawncare machines. Even gutters with leaf guards can have leaves build up along roof valleys. Drain water hoses, add protective insulated boxes over outdoor water spigots, and take expensive watering wands indoors for the length of cold weather. These can freeze and break if they hold water in their sprinkler heads. Empty garden fountains and store delicate containers in a freeze-proof area. Indoors, replace furnace filters and the batteries in smoke detectors. Most important, schedule time to relax in front of your fireplace with seed catalogs and a sketch pad, planning for next year.

An image of my driveway from last year. Thanks to the numerous trees brought down by Hurricane Helene, this year’s appearance will be markedly different.

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.

Plant Bulbs Now For Spring Color

The official beginning of autumn fell earlier this week, the autumnal equinox. It was ninety degrees here, so it didn’t feel very fall-like. This day marks the beginning of nights being longer than days. Days get progressively shorter and nights get longer until we reach the winter solstice, when the trend reverses. To gardeners, the autumnal equinox means it is time to stop delaying and order those bulbs that will be planted now for flowers next spring.

Almost every garden can benefit from the addition of spring-flowering bulbs, whether that is “true” bulbs like daffodils and tulips, or corms, tubers, or rhizomes. I have a special appreciation for bulbs because most of them flower very early, before annuals and perennials have started blooming. Those early flowers give me an emotional boost, reminding me that the cold part of the year is reaching an end and that the garden season will soon begin.

If you are new to gardening or if you are trying to help someone develop an interest, bulbs are a good place to start. The majority are low maintenance. Beyond the task of digging the holes and dropping in the bulbs, bulbs don’t demand much except for an occasional sprinkle of lime or fertilizer. When flowering has finished and the foliage has withered to brown, it can be removed. Bulbs then remain dormant until next spring, when they push their foliage and buds through cold soil to bloom again.

Daffodils are easy and reliable, a good place for beginners or black-thumb gardeners to start. They are available with early, mid-season, or late spring flowering period, and a wide variety of flower types. For the best appearance in the garden, start with a large group of just one type (King Alfred daffodils are a sunny yellow, strong grower that you can find in every big box store at very reasonable prices) and plant them in groups. A grouping makes an impact, while dotting them about in ones or twos just makes flowers look sad and lonely. Check the package instructions for ideal planting depths. I use a bulb auger (looks like a giant drill bit) in my cordless drill to dig holes quickly and easily. It can be difficult to visualize the exact underground distance of your hole, so use a piece of colored duct tape on the augur to mark the desired depth. Keep holes a consistent depth so they all flower at the same time.

Happy bulbs will produce offsets. Once these offsets become numerous, the foliage becomes congested and flowering is reduced. This is an indicator that bulbs should be lifted, separated, and replanted. While one should do this separation and replant process while the bulbs are dormant, I have difficulty in locating them when they are without leaves, so I divide mine just as soon as they start showing signs of spring foliage. While this is not the textbook recommendation, it does not appear to have much of a negative impact on flowering.

Daffodils are an easy choice, but tiny little crocus bulbs flower even earlier, occasionally appearing through snow. Remember snow? My part of the southeast hasn’t seen too much of it in the last few years. Crocus bulbs (corms) are small which makes them a breeze to plant, but also means you need more of them to make a visual impact. Other easy choices are Allium (flowering onion), Ipheion (blue star flower), Muscari (grape hyacinths), Gladiolus, and Squill. I love Tulips, but recent southeastern winters have been a little too warm to give them the cold period they need to appear at their best.

It is almost inevitable – Once a new gardener has experienced success with the easy spring bulbs listed above, an appetite follows for expanding to other types of bulbs. There are bulbs that flower in summer, fall, and winter, so find a reliable seller and expand your choices. My favorite source for ordering bulbs is Brent and Becky’s Bulbs, from Gloucester, Virginia (www.brentandbeckysbulbs.com). Some top-notch local nurseries have a wide assortment of bulbs that are priced individually, allowing you to buy the exact number that you want. Just don’t wait too long to purchase. Popular choices may sell out early.

Bald Cypress, Deciduous Conifer

Bald Cypress, Taxodium distichum (pronounced taks-O-di-um DIS-ti-kum) is an unusual native. It is one of a very small group of trees that are deciduous conifers. The bark of young trees exfoliates in long strips, revealing a warm cinnamon color underneath. It has two types of seed cones. Female cones are large marble-sized green balls held at the ends of it branches, while the male cones are pendulous, darker, and held closer to the tree’s upper interior. Although the tree has tough wood and tolerates heat and humidity, the feathery foliage looks soft and delicate. Needles spiral around the stems. Most trees have an attractive coppery-brown fall color before the feathers shed.

Bald Cypress grows well in coastal areas where it is known for pushing up “knees” when grown in swampy or water-logged soils. Many coastal trees are festooned with Spanish moss. The tree’s tolerance for low-oxygen soils makes it a great choice for heavy clay (read: low oxygen centent) soils in non-coastal areas.

Bald Cypress is hardy in zones 4-9. It needs full sun and acid soil, as trees exhibit an unhealthy yellowing (chlorosis) in alkaline soils. Trees are resistant to damage by deer. Mature trees can reach heights up to 70 feet and widths to 30 feet. The dwarf cultivar ‘Peve Minaret’ reaches 20 feet, despite early labels that called for a maximum height of 8 feet. Several weeping forms are available. Green Whisper® (‘JFS-SGPN’) was discovered in South Carolina and has a warmer, almost orange fall color. Shawnee Brave™ (‘Mickelson’) is widely available, and has a narrow pyramidal form.

Low maintenance and heat tolerance make Bald Cypress a good choice for street trees. Growth rate is moderate to rapid, making the narrow forms an option for planting in new subdivisions, where other trees might struggle in compacted soil of low fertility.

Feathery foliage of Bald Cypress. Photo by Cathy Dewitt CC BY 4.0

Female Bald Cypress seed cones. Photo by Synezis CC BY-SA 4.0

Fall color and form of ‘Shawnee Brave.’ Photo by Jim Robbins CC BY-NC-ND 4.0

Wonderful Blue Winged Wasps

I have a new, favorite insect: blue-winged wasps. Some of you may recall that last year I had enormous numbers of June bugs and Japanese beetles hovering over the pasture next to my orchard. (If you want a refresher, click HERE.) At the time, I was determined to purchase and apply a product to kill the grubs that hatch into these eating machines. Life got in the way, and I never did the research to determine which grub killer was the best choice – you know, the right product to address these specific insects, toxic enough to be effective but not so toxic that it would kill beneficial insects. So, the year went by without any insecticide application. And Mother Nature did the work for me, free of charge.

Scolia dubia, commonly known as two-spotted scoliid wasps, blue-winged scoliid wasps or digger wasps, have pretty blue wings, black head and thorax with a rusty-colored abdomen, with a couple of yellow blobs on their rear segments. Females are not aggressive, and won’t sting you unless you really, really mess with them. Males do not have the capacity to sting. They will let you get up close and personal with a cell phone. Despite groups of them congregating in the late afternoon on the wires of my protective cages around blueberry plants, they are known as solitary wasps. This means that they nest alone and feed their babies alone, unlike hornets or paper wasps that live in communes.

When I see large number of these wasps zooming around the pasture just a few inches above the ground, they are shopping for a family dinner. Guess what is on the menu? It is the white grubs that develop into June bugs and Japanese beetles! When the wasp detects a grub, she dives into the soil (see common names above – “digger” wasps) and paralyzes the grub with a sting, then lays her egg on the grub’s body. When the egg hatches, the hatchling’s first meal – a dinner that lasts about two weeks -- is the paralyzed grub. The wasp larva spins a cocoon and becomes a prepupa in the Fall and rests during winter. As warm temperatures return, the prepupa becomes a pupa, which then molts into an adult that emerges in the Spring.

While any insect that hunts and destroys Japanese beetle grubs is a hero in my estimation, blue-winged wasps are also good pollinators. They visit goldenrod often, so check yours out to see if you are hosting these very good bugs.

Blue-winged wasps congregate on fence wire just before dusk.

This blue winged wasp has a dusting of pollen on her head after visiting the nearby pollinator garden.

Not a great photo, but this wasp has detected a white grub under the turf. She drove into the ground and emerged after depositing her egg on the grub.

Passionflower Pops In The Garden

When we first moved to our current property, I was excited to find Maypop plants (Passiflora incarnata, pronounced pas-si-FLOR-ah in-kar-NAH-tuh) growing. This native vine tolerates heat and drought. I found it in sunny areas as well as partly sunny areas, on inhospitable soils that receive no supplemental irrigation. Maypop is cold hardy in zones 5-9. It borders on aggressive in the Snoddy garden. I have tried to eradicate it in several unwanted locations, but it springs back to life from its deep roots. It grows very rapidly, and can be used as a groundcover.

Another common name for Maypop is Passionflower. The intricate flowers are purple and white, with a central structure that was used by Catholic priests in the 16th century to symbolize or describe the crucifixion of Jesus Christ, the passion. How did the common name arise? Well, if you step on one of the fruits, it “may pop.”

I allowed several vines to remain in the pollinator bed next to our orchard (okay, I got lazy and allowed them to flourish unchecked). The flowers are beautiful, unlike anything else. I was looking forward to eating the egg-size fruit, which is reputed to be delicious. The internal structure is similar to pomegranate. I kept an eye on them, ready to harvest as soon as the lime-green fruits turned yellow. Unfortunately, the wild creatures that live in our woodlands are not so patient. They removed the almost-ripe fruits from my vines. All but one, and that one lonely survivor showed teeth marks from either groundhogs, opossums, skunks, or rabbits. Sorry, I don’t share food with rodents.

Even without harvesting a single fruit, I am glad that I allowed the vines to remain. Their leaves have fed a number of different larvae and adult butterflies have flocked to the flowers. A common name for the Gulf fritillary butterfly is passion butterfly. While Maypop fruit is edible, the vine stems and leaves are toxic to humans, dogs, cats, and horses. Deer leave the vines untouched, but Japanese beetles devour the foliage. Despite its toxicity, Maypop would make a great addition to a pollinator garden, especially when planted in a container to eliminate root spread and given a trellis to support its climbing via tendrils.  One trusted university source says that the vines are extremely flammable and should not be planted near the home.