The Green Hell Lives

May 17, 2010 4:47 PM

Kudzu, Pueraria lobata, may be causing double the emission of nitric oxide, and increases ozone pollution in areas it has overgrown, a recent study has shown.

First introduced at the Centennial Exposition as an ornamental plant 1876 from Japan, thanks to its lovely flowers. It now constitutes an invasive species and is classified by the USDA as a noxious weed, and is common throughout most of the south eastern US. Planted widely by the Soil Conservation Service (now the Natural Resources Conservation Service) between 1935 and 1950, the spread of the plant has been virtually unchecked except by adverse growing conditions.

The study shows that the plant's very efficient nitrogen fixing properties increase the output of nitrogen by affected soils as part of their cycling, greatly increasing the level of nitric oxide in the area. As well, the plant is highly efficient at outputting oxygen, leading to an increase of high level O2 events in areas with kudzu infestations.

posted by strixus (33 comments total)

Noxious weed, indeed! This puts the other "baddies" to shame.
posted by filthy light thief at 4:57 PM on May 17, 2010

We all have noxious needs if we'd only admit it.
posted by oneswellfoop at 4:57 PM on May 17, 2010

Too bad you can't smoke it. On the other hand, it might help you stop smoking.
posted by HP LaserJet P10006 at 5:00 PM on May 17, 2010

I read that kudzu was introduced as a cheap source of cow feed. But it turns out that, as the saying goes, "a cow won't eat kudzu, but kudzu will eat a cow."

Strangely enough it can be turned into a tasty preserve and a sweet-scented candle, if my Indianola gift shop experiences are to be trusted. Maybe the jam's just pear-juice-flavored and the candle off-the-shelf wax with bits of kudzu in it, to make the stuff marketable somehow. But I do see "kuzu flakes" in the local organic market next to the seaweed in the Japanese-food section, so I guess it has some pectin-like properties.
posted by Countess Elena at 5:00 PM on May 17, 2010

Man, good luck getting rid of the stuff. It grows like kudzu.
posted by mudpuppie at 5:03 PM on May 17, 2010 [3 favorites]

The Kudzu Conspiracy [.pdf]
posted by HP LaserJet P10006 at 5:04 PM on May 17, 2010

On a personal note - I had a great uncle who lost a prize goat to kudzu. The goat ate QUITE a lot of it, became bloated, and died of intestinal rupture. Not a pretty sight.
posted by strixus at 5:07 PM on May 17, 2010

If kudzu somehow gets crossed with bamboo, then say hello to your new plant overlord.
posted by jefbla at 5:18 PM on May 17, 2010

Kudzu doesn't sleep. It waits.
posted by Rhaomi at 5:27 PM on May 17, 2010 [9 favorites]

Nature's Christo.
posted by hal9k at 5:47 PM on May 17, 2010 [4 favorites]

Too bad you can't smoke it.

You can definitely eat it. You can dry kuzu to make a kind of flour, which can be used to create jelly. Yum. It's a Japanese thing
posted by KokuRyu at 6:38 PM on May 17, 2010

I once saw (but sadly didn't buy) a book on papermaking from various plant matter. The book had directions for making paper from just about everything, including corn husks (they said it would make a creamy light green paper), to, yes, kudzu.

The instructions for kudzu came with several warnings, mentioning that not only was it illegal to take kudzu into several states (the list was quite long), but it also mentioned that if, after drying, the paper got wet, the kudzu will start growing again.

It doesn't feel pity, or remorse. And it will not stop until your yard is dead.
posted by Ghidorah at 6:42 PM on May 17, 2010 [1 favorite]

Kudzu came up in Salem's Lot, I think. I think it's after the priest is gotten. It seems, in retrospect, one of King's random vaguely druggy things that sort of disappeared from his writing when he sobered up.
posted by angrycat at 6:43 PM on May 17, 2010

Supposedly the roots make a hangover cure. Still, I've never known anyone who has tried it and there must be easier methods.
posted by mygothlaundry at 7:13 PM on May 17, 2010

I come from farming folk in south central Arkansas, so I know kudzu is evil. But damn, it sure is beautiful. A forest draped in kudzu is dying, but it has a lush, otherworldly quality that is just extraordinary.
posted by Mavri at 7:32 PM on May 17, 2010 [3 favorites]

Stuff grows so fast I swear I *saw* it growing one particularly hot, muggy Alabama summer.
posted by gjc at 7:38 PM on May 17, 2010

In an attempt to retrieve a toolbox (long story), I once tumbled down a steeper-than-anticipated kudzu-choked hill into what I discovered was a muddy ditch. The kudzu was over my head. I was certain I would be bitten by a snake and die right there and the kudzu would envelop me and my body would never be found.

Instead I found the toolbox and waded back up the hill, trying really hard not to think about snakes.
posted by BitterOldPunk at 7:51 PM on May 17, 2010 [2 favorites]

It grows so fast it's been know to swallow slow moving cows.
At least I've heard that, and I live in Virginia.
posted by PHINC at 8:34 PM on May 17, 2010

Those pictures are terrifying. I keep thinking Cthulhu is behind this, using kudzu to cover and consume the world.
posted by Pope Guilty at 8:38 PM on May 17, 2010

I used to live in Georgia and always heard urban legends about people falling asleep in their yards, only to wake up covered in kuzu from a nearby field.

You can make a good jelly from the flowers, but the leaves are not that great.
posted by bradbane at 9:20 PM on May 17, 2010

I always wondered...why isn't Japan as covered by Kudzu as the American south is?
posted by swimming naked when the tide goes out at 9:42 PM on May 17, 2010

Godzilla does excellent hedge work.
posted by Ghidorah at 9:47 PM on May 17, 2010 [1 favorite]

why isn't Japan as covered by Kudzu as the American south is?

Kudzu was actively promoted during the early 1900s as food for livestock in drought-prone areas and was being planted as ground cover for erosion control along highways as late as the 1960s.
posted by mediareport at 10:27 PM on May 17, 2010

(in the US, I mean, which probably accounts for the difference)
posted by mediareport at 10:28 PM on May 17, 2010

I always wondered...why isn't Japan as covered by Kudzu as the American south is?

Hard freezes will kill kudzu back to the roots. Continuing hard freezes will kill it altogether.

The invasive characteristics of kudzu are promoted by high humidity and warm temperatures--such as the Deep South is famous for. It is noteworthy that the original importation of kudzu into the South (c. 1920) was to stabilize railroad embankments. Sufifce to say, it was good for that. And then. . .
posted by rdone at 10:32 PM on May 17, 2010

Yeah, just came back to make rdone's point about the lack of hard freezes in the South - that's key.
posted by mediareport at 10:36 PM on May 17, 2010

This might help explain why even more rural areas of Georgia have higher than expected levels of air pollution typically linked to traffic.
posted by Megafly at 10:43 PM on May 17, 2010

I can testify first-hand to kudzu's horror-movie qualities. When I moved into a house in the South, it was one of the first things that I noticed about the semi-neglected property; it had grown from the ground up along a guy wire that held up a utility pole, then crept along the horizontal wire and dropped down in a big green curtain that was not only threatening to pull down the telephone wire to our house, but also affected other plant growth in our back yard by blocking out sunlight for a good part of the day. We called the utility company, which came and sprayed weed-killer on the kudzu growing on their wires... and before the existing plant growth had finished dying, fresh kudzu tendrils had started growing up the guy wire. We'd also find tendrils poking out through the cyclone fence around our yard, literally reaching out to ours from our neighbor's yard, where none had been the night before.

One of the reasons for kudzu's tenacity is that it's not easy to eradicate. The roots grow up to seven or eight feet in length, and even though they grow horizontally through the soil (at least they did in the thin layer of topsoil that covered the clay in our neck of the woods), they're fragile enough that you can't just pull them up--they need to be carefully excavated. Believe me, you think you know about pest plants from dealing with dandelions and crabgrass, you just don't know. We ended up pulling out a minivan-sized pile of kudzu from our back yard, and ours wasn't the worst case, not by a long shot. When we'd go driving out in the country, I'd see what I'd call "kudzu parliaments"--hillsides of formerly-thriving trees that had been covered with kudzu and killed by its leaves covering the trees' own (as in Rhaomi's links above), their semi-anthropomorphic, saguaro-ish ranks a mute testimony to the bastard weed's implacable hunger.
posted by Halloween Jack at 5:29 AM on May 18, 2010 [3 favorites]

> a cow won't eat kudzu, but kudzu will eat a cow

Goats will eat kudzu quite happily--in fact you may have to take steps to make them stop eating it before they make themselves sick.

Also, people can eat kudzu. Leaves, flowers, roots, nothing left but the demon shriek. linkie - linkie - linkie. - What keeps it from overrunning China, where it's native? 1.3 billion Chinese.
posted by jfuller at 6:42 AM on May 18, 2010 [1 favorite]

A hard freeze won't kill it. We get them all the time up here in the mountains - last January we had two straight weeks of sub teen temperatures - and the kudzu is still here, still doing its kudzu thing.
posted by mygothlaundry at 10:35 AM on May 18, 2010

mygothlaundry: It has to be a sustained enough freeze that the frost line moves down the entire root system.
posted by Justinian at 12:08 PM on May 18, 2010

Just to make it even better, kudzu is a host for soybean rust. The rust overwinters on kudzu in the deep south, and then the rust spores blow North in the spring to infect soybean.
posted by acrasis at 4:50 PM on May 18, 2010

Everything I know about Kudzu I learned in a little book.

We walk!
posted by JBennett at 9:31 AM on May 19, 2010