Monday, August 1, 2011


The amorphous malaise continues. Maybe I’ve developed a sensitivity to increased atmospheric carbon dioxide. Regardless of what my problem is, burgeoning CO2 levels makes vining plants very happy indeed. In 2007, USDA scientist Lewis Ziska published a study in Weed Science saying that, since the 1950s, vines grow more vigorously and spread with devil-may-care aplomb; they’re harder to kill; and, most ominous of all, the effects of the itchy-rashy substances in the skin-irritating ones are magnified.  If you’ve battled any of the following in your yard, you know he's right.

Poison ivy counts as the worst offender by my reckoning. Urushiol, the chemical that causes the irritation, rash, blistering, oozing and itch, is present in the leaves, stems, woody parts and roots. It remains active even after the plant dies. Some hyper-sensitive unfortunates even react if exposed to the smoke of burning poison ivy, developing lesions in their mouths, noses, throats and lungs. Can you imagine?

Poison ivy, with leaves of three
Toxicodendron radicans
            Growing up in the swamps of southeastern Virginia provided opportunities aplenty for close encounters: Girl Scout Camp Skimino was redolent with the appropriately named Toxicodendron radicans (the genus translates to “poisonous wood”). My dearest childhood friend, Ginny Black, had only to pass within 30 feet of a strand to start scratching. Because children are cruel, all of the urushiol-invulnerable Scouts giggled at her misery. In those days, I could roll in the stuff and suffer no ill effect.  The day I turned 50, however, my immunity switched off. If balance exists in the universe, as I believe it does, Ginny’s curse disappeared around the same time, and she gets the last laugh. Fifteen to 30% of people are completely immune: the rest suffer at differing times in their lives (like Ginny and me) and with differing intensities.

More deeply lobed poison oak leaflets
Toxicodendron pubescens
Regarding poison ivy, our Scout handbook taught us the ditty, “Leaves of three, let it be.” This is sound advice for the fearful, akin to “Better safe than sorry.” One of life’s little ironies, it’s easier said than done for those gathering wood for the campfire, and for those laboring in gardens of their own or others. Learning to recognize plants that contain urushiol is the best defense. The three commonest offenders are poison ivy, Atlantic poison oak (Toxicodendron pubescens), and poison sumac (T. vernix). I include pictures of all of them here, and links to websites with more information.

Poison sumac doesn't follow
the "leaves of three" dictum
Toxicodendron vernix
Southeastern North Carolinians only need worry about the first two: mercifully, poison sumac doesn’t grow here. I say “mercifully” because the “leaves of three” dictum doesn’t apply. Poison sumac looks like, well, non-poison sumac. Poison oak is indigenous to the south, ranging from New Jersey to Kansas, and south to Florida and Texas, except for Pennsylvania, Ohio, Indiana and Kentucky. Go figure. Poison ivy is native to all of North America east of the Rockies plus Arizona, but not in New Mexico, North Dakota, Newfoundland and Labrador.

Why is there poison ivy? Non-human animals seem urushiol-proof: many eat it with gusto, and the berries are a great favorite of many birds. Another sorrowful mystery for the books. For rash palliatives, go to December 10, 2010's post, "Stuffing Stockings." 

I’m starting to itch, so it’s time to move on to less painful but just-as-vigorous vining plants liable to turn up in your yard.

Virginia creeper creeps
up a tree in a vacant lot
Parthenocissus quinquefolia
Virginia creeper (Parthenocissus quinquefolia) often gets mistaken for poison ivy because seed leaves have three leaflets instead of the characteristic five of older foliage. Native to eastern and central North America, it can actually be purchased and planted on purpose as an ornamental vine, mainly due to its brilliant red fall coloration. A vigorous climber—up to 30 feet—it attaches itself to supports by means of flat discs at the end of its tendrils. The problem with creeper is that it pops up unbidden EVERYWHERE in my neighborhood. And while it doesn’t strangle the trees it obscures, its exuberant growth tends to smother them to the point of inhibiting photosynthesis. I’m just sayin’.

            Kind of like kudzu. Kudzu (Pueraria lobata) is the poster child for non-native invasive plants. (The whole native/non-native, invasive vs. biodynamic issue will be the subject of a future post.) We don’t see a lot of it very near the coast—salt may affect it adversely—but it’s certainly ubiquitous inland, where it out-competes anything else, including slow-moving creatures. Kudzu is probably the reason there are no North American sloths. It primarily spreads by shooting out above-ground stolons and sub-surface rhizomes. I include a picture of its pretty though inconspicuous flower. Allegedly, the fruits make scrumptious jellies, and fragrant soaps and lotions. Originally imported from Japan as a fast-growing, adaptable bovine fodder, when agribusiness decided to start raising cattle in concentrated feedlots and force-feeding them grain instead of the forbs they’d rather consume, there weren’t enough pasture-raised cows left to eat what kudzu had been planted. The rest—along with mad-cow disease and rising growth-hormone levels and antibiotic resistance in humans—is history.

The lovely kudzu flower

Kudzu doing its thing
Pueraria lobata


Another rampant vine of southeastern landscapes is the scuppernong grape (Vitis rotundifolia). The oldest cultivated grape in the U.S., the 400-year-old “Mother Vine” still grows on Roanoke Island, NC. A variety of Muscadine, scuppernong can be found in the wild all over the South. I transplanted a specimen from the vacant lot next door to our outdoor shower, hoping for future harvests. Scuppernong grapes are an acquired taste, as they have seeds and bitter skins. Scuppernong grape vines are notoriously difficult to get rid of once they establish a foothold where you don’t want them. The woody vines don’t pull out easily, and the roots of all of them, it’s rumored, extend back to the mother plant just outside of Manteo.

Transplanted scuppernong vine
takes hold on our outdoor shower

Scuppernong grape vine
making itself at home
Vitis rotundifolia


Bramble blackberry vine in situ
Rubus vulgaris

You can’t catalog miserable vines with edible fruits without mentioning good ol’ Rubus vulgaris, the bramble blackberry briar. Bramble blackberry is a weed of cultivation, appearing in disturbed soils. Spreading by rhizomes to form impenetrable thickets, it guards its delectable fruit by skazillions of evilly hooked thorns. I know of a large patch (the location of which I reveal to no one), and am willing to accept the blood-sacrifice required to harvest the small, intensely flavorful berries. This is not a plant I want in taking hold in my yard, however. Intruders get summarily yanked out as soon as I spot them, such as the one pictured here.

Close up  of bramble blackberry vine
at left, pulled out of the ground

Cat brier,
a.k.a roundleaf greenbrier
Smilax rotundifolia
(Note lack of thorns and
 heart-shaped leaves) 
Cat briers get the same treatment, only with less happy results. Sometimes known as greenbrier, Smilax spp. is a native of southeastern and central states, roughly similar in range to poison oak. Its most common name derives from the cat-claw-like thorns clothing the stems. You can also call it carrion flower, because, dependent on flies for pollination, its blooms stink like, er, dead things. Fortunately for us, they’re inconspicuous. Familiar species include S. bona-nox (saw greenbrier) and S. rotundifolia (roundleaf greenbrier), pictured here.  Cat brier’s apparent immortality arises from the woody tuber at its base. These tubers, notoriously difficult to dig out given their propensity to intertwine with the roots of desirable plants, can reach the size of russet potatoes. Tim and I knew a guy who carved whimsical animals and such out of them: he certainly didn’t have to worry about running out of raw material. (There's a good picture of a typical tuber at Click to view all nine photos at left; click again to enlarge the shot by Podster. I can't use it without authorization, and I don't want to piss Dave off.) The more enterprising among you may be pleased to learn that Smilax tubers are the source of sarsaparilla (not “SASS-parilla,” as I’ve always heard it said), if you want to go to the trouble of excavating them. Some Smilax species have smaller thorns, or none at all. These latter occasionally turn up in the trade as an ornamental vine. I can only shake my head in disbelief.
Cat brier,
a.k.a saw greenbrier
Smilax bona-nox
(Note thorns and
 silvery blotches
on arrowhead-shaped leaves)

 And no, I don’t know why it’s spelled “brier” instead of “briar.”

To rid your landscape of any of these vines, I recommend pulling. And pulling. And pulling. None of them have roots that pop readily out of the ground, so what you’re trying to do is starve them to death by depriving them of the ability to photosynthesize. It takes a while, but it works. It is also the most sustainable and environmentally responsible control method out there. Roundup doesn’t work on woody plants (regardless of what Monsanto may have led you to believe), so don’t bother.

The problem with vast empty spaces has raised its ugly head again. If anyone knows how to fix it, or avoid it, please clue me in.

Well, that’s enough for today. My deepest, sincerest apologies to the Sondeys, in whose yard we were supposed to be working today. I swear, we’ll be there tomorrow.

To the rest of you, thanks for dropping by.