DECEMBER, CROP FiELDs ACROss INDIANA and Illinois, en route to Missouri
My husband has great longevity genes: three of his four grandparents are still living, all around age ninety. What's more, they all live in the same small town in south-central Missouri, not far from Springfield. The fact that they have made it this long and are all so conveniently located in the same town puts visiting them regularly at a high priority for us as a family, and if we go during the holidays we get the bonus of visiting with Brian's cousins, uncles, and aunts. Plus, Brian's maternal grandparents still have plenty of good farm entertainment for the girls: chickens, turkeys, cattle, dogs, and cats. So, despite the ordeal of a fifteen-plus-hour car trip, every other December we trek from Pittsburgh to Missouri to spend the holidays with my extended in-laws.
The car trip itself can be a worthwhile experience, even though I'm always glad when we arrive at our destination. One thing I like about car travel in winter is that with all the windows in a car, we get a lot of time soaking up the little bit of available daylight. We pass through the southern ends of Ohio, Indiana, and Illinois, not relentlessly flat, but mostly wide open farmland punctuated by cities and outlet malls. We see hawks and deer often and occasionally see white, fierce, fast-flying osprey or gangly, prehistoric-looking herons.
Farm fields in winter may seem dull, but they became much more interesting to me after all my courses and research on agriculture. I can see if the soil is lumpy and fresh turned, showing whether and when (fall or spring) the farmer tills the field, I can see the occasional cover crop like clover or rye, planted to prevent erosion in winter, between corn or soybean crops. Often, even traveling at sixty-five miles per hour, I can identify weeds in the field (and, as a bonus, since we don't slow down to look closely, I never know if I am wrong).
From experience I know that two of the most common winter types of weeds in crop fields include low-growing mints, such as purple-tinted deadnettle or the somewhat greener henbit; or chickweed, either the aptly named mouse-ear chickweed, with small fuzzy leaves, or the similar fuzz-free version, common chickweed. Mouse-ear chickweed (Cerastium vulgatum) and common chick-weed (Stellaria media), both with small white flowers, have tiny leaves, somewhere between diamond- and spade-shaped, paired on opposite sides of the stem. These plants are all small and low-growing—just lawn height—and seemingly innocuous, hardly worth notice. Farmers, in fact, take little notice of them at all, unless they're growing in a winter crop like wheat.
These weeds also grace our gardens, though we tend to be more bothered by them than farmers are. Every gardener has what I would consider primarily a nuisance weed in the garden, and the chickweeds are in this category. These weeds are small and spindly, but they spread. In my garden, their seeds seem to disperse approximately one second before I reach out to pull the plant. None of these nuisance weeds are worth spraying for corn or soybean farmers, because they're too small to threaten a big, healthy crop, though many are aggravating in smaller vegetable crops.
Many of these little nuisances have charming names that could just as easily be garden flower names, but their flowers are either too small or nondescript to be worth cultivation. I spoke of scarlet pimpernel and creeping veronica in summer. Yellow wood sorrel (Oxalis europaea) or the similar creeping wood sorrel (Oxalis corniculata) both have edible, tangy, clover-like leaves and small yellow five-petaled flowers. Cuckooflower (Cardamine pratensis) begins the winter with a rosette of ornately divided leaves and in spring sends up stalks of small, four-petaled white flowers, which later turn into crazily exploding seed pods, which probably inspire the common name.
Others have stranger-sounding names. Small, purple, bee-luring flowers grace several common, unfortunately scentless, mints such as henbit (Lamium amplexicaule), purple dead nettle (Lamium pur-pureum), and ground ivy (Glechoma hederacea). These mints are attractive, even beautiful, at their best moments, but I've heard complaints from even the most tolerant lawn owners because of their ability to spread over thickly mulched surfaces. Many gardeners consider them something between a nuisance and pure evil.
In my flower beds, I pull most of these little weeds, if I'm in the mood or if they seem to be getting especially uppity in their infestation. Chickweed and these other little winter-growing lawn plants, though, make their living by stealth reproduction at the close of winter. While we are busy tending the larger, more beautiful garden plants in early summer, chickweed is producing tiny, sneaky seeds that seem ready to release the moment the plant seems large enough to be worth pulling. Although a vigilant all-season gardener can keep them out, many a more relaxed or fair weather gardener has had the experience of suddenly noticing that the entire under-story of her flower bed is thick with tiny green chickweed.
In the garden, pulling these plants is preventive maintenance. Perhaps because gardens already have plenty of room for diversity, I have no problem with the idea that weeds don't need room left for them. I figure if a person doesn't like pulling or hoeing weeds from a garden, the solution is simply to keep less garden space. Most gardens aren't useful places for herbicides anyway, because the plant value and diversity make herbicides more of a risk than a benefit.
But in the lawn, these plants practically belong. In winter, they are green and ready to grow when so much else is brown and dead. Like scarlet pimpernel, these plants all bear less than a dime-sized flower; unlike scarlet pimpernel, the flowers of all but the mints are nondescript, a single color, pale yellow or plain white. The mints definitely win the beauty prize of the list, as a thick clump of them can appear as solid lavender from a distance. The mints are green in winter, though the upper leaves of the one called purple dead-nettle have a purple sheen to them. The main fault of the chickweeds is that they are annuals—ultimately they turn brown and ugly, dying back before time for their offspring to germinate. At the same time, this characteristic makes them relatively unthreatening to a healthy perennial lawn, where there are no spaces to colonize.
In fall semester, when I want students to see these plants, we generally have to look at the edges of lawns, near buildings, where heavy shade makes lawn growth thinner. I enjoy these plants for identification practice, because their reliable presence makes them like permanent teaching assistants, like the friendly colleague you can count on to ask the first audience question after your public presentation. I know where they grow, so there is little question that I will find them as I wander about the college lawns. To the students, though, I suspect every time I take a class outside with plant identification guides that they believe I know all the plants. Instead, I am taking the students to the few places where all the plants I know live. In lawns, I'm not generally looking for strange new specimens, but for old friends.
One of the primary rules of weed science is that weeds compete most with crops whose life cycles match those of the weed itself. Corn weeds, unsprayed, sprout in spring the morning after the planter passes, and grow tall and parallel with the corn, matching or surpassing the crop in height. The most troublesome of these grow large like the corn. Giant common cocklebur with its Velcro-inspiring burrs grows to the heights of the average suburbanite. Soft-leaved velvetleaf, a plant introduced to produce fiber like cotton (it doesn't), can be the size of a healthy young poplar tree by August. Pigweed has smaller leaves than cocklebur or velvetleaf, but also has a mighty, thick stalk, and seeds that number in the thousands. These large weeds—all summer annuals, like corn—can grow faster than the corn and disperse seeds before the first ear is ready to pick. These seeds then lie dormant through winter, programmed to avoid germination until the time when the field is likely tilled and planted the next year.
The winter annuals are a smaller set generally, and the time of their germination is when winter wheat is in the ground, itself green and building root reserves for spring takeoff. They and the wheat stay green through the winter, quiet and ready for the occasional warm day for a dose of sun, but mostly just waiting until spring's first warmth announces the time for flowering and seed-making. And in those warm spring days, the winter annual weeds grow and set seed quickly, before the stronger summer annuals can shade them.
One of the efforts of my mentors in graduate school was to reduce soil erosion. The Dust Bowl is famous for the drama of its soil erosion; no other agricultural problem has been the subject of song so often. Nancy Griffith, in "This Old Town," and Natalie Merchant, in "Dust Bowl," sing about the perseverance and grit of those times, with nostalgic melodies that make the period seem full of heroism and hope. The Dust Bowl of the 1930s is now long past, but soil erosion continues eternally, usually without our notice. The problem is acute in windswept flatlands — increasingly so as we deplete our aquifers in the U.S. Southwest—but also on hilly northeastern farms. The Soil Conservation Service was founded in the 1930s to study and alleviate the problem, and one of the resulting guidelines is that vulnerable agricultural soil should have about one-third coverage—by dead or live plant material—to prevent excessive erosion. In the Northeast, the erosion problem is most acute in winter, in between corn crops so often grown by dairy farmers for winter feed. When corn is harvested for grain, enough plant material from stalks is left to provide sufficient ground cover, but when whole plants of corn are harvested and chopped for cattle food as silage, little is left to prevent the soil from blowing away.
Northeastern dairy farms tend to be on hilly land, and silage is frequently one of the crops of choice farmers grow for feed. Erosion is definitely a concern. Corn and soybean fields in winter are often covered with winter annuals, weeds that most farmers ignore because they will be destroyed with the simplest of spring tillage.
Though some farmers plant cover crops—rye, most commonly, but sometimes clover or its cousins—winter annuals such as chickweed and purple deadnettle cover fields for free. I've never heard a farmer speak about these weeds, but farmers are businesspeople, and they won't typically waste money to spray a plant that isn't doing any significant economic damage to their crops.
Who hasn't thought or heard a statement like this: "If you don't take care of that weed, it will take over and choke everything else out"? I've even seen it happen—purple loosestrife filling a whole wetland with its colorful but choking blooms, kudzu thickly covering trees and buildings alike, Japanese knotweed covering a whole hillside with its woody stems and massive leaves. I believe that weeds can do this, in limited spaces at least. I've counted weed seedlings in crop fields, and found more tiny, insidiously germinating lamb's-quarters than crop plants—the weeds so thick that if they are not controlled, they will be stealing more light and water from each other in a day than the crop can soak up in a week.
Is it true that weeds will take over completely—even our homes! — if we don't stop them? If the neighbor's dandelions go to seed, that our lawns will be completely overtaken by them? Though some weeds can do this, given open-season opportunity on a plowed field or hillside, in most places weeds are just plants with a bad reputation. They're subject to the same limits as all the other plants. Eventually, of course, if you planted nothing in your garden, the weeds would grow—what self-respecting plant wouldn't grow in the lovely rich topsoil of your garden! But even then, they'd grow in a mixture, a patch of dandelion here, a jimsonweed there, some crabgrass over yonder. That mixture would, left unchecked, grow thick and tall, but the next year, some thistles or mullein might take root and overgrow the weeds of last year. Yes, weeds collectively will take over, but really, without our intervention all that happens is they start competing with each other instead of having to fight with us and our wimpy garden plants.
I don't know exactly what I thought about weeds before studying them, but I do remember realizing, with a touch of surprise, that plants have limited body sizes, just as we do. Chickweed left untended—even fertilized and watered and given supplemental lighting—will never reach the size of a rosebush; a dandelion can get shockingly lush in a vacant lot or in untended mulch, but even a dandelion will never sprout a real stem and grow tall. This is obvious, of course, but I think the idea of what kudzu can do had covered over all reasonable ideas about how each weed is an individual, with its own limitations. The dandelion gone to seed may produce hundreds of offspring, but each one has to start fresh as a seedling, and without light, water, and nutrients the seedlings will be as vulnerable as any newborn. Pulling dandelions is easy, if they haven't spent years expanding their taproot while we ignore them.
I'm not arguing that we leave all those little weeds, just because they won't overtop the daffodils, but I would say we needn't treat them as if they're dangerous, any more so than dust under the bed. Every single person tending even the smallest plot of land will see one of these weeds — my mother-in-law worries over the ground ivy (a mint), my garden sprouts yellow wood sorrel in quantities I can't come close to consuming, and even my husband has come to regret that we let cuckooflower thrive in our garden the first summer, just because it is in his favorite plant family. But really, the reason these little weeds continue to thrive is that they are so small that their presence is hardly noticeable even in populations the size of kindergarten classes.
It is the thick of winter when I most admire chickweed. In December, when we're driving sixty-five miles an hour across the Corn Belt, any little plant covering bare ground is doing us all a favor. Over the holidays, there are many other little green elves doing nice things for people, without necessarily drawing a lot of attention to themselves. They don't work for Santa. Tiny, elfin chickweed in winter is making us a present we couldn't afford to buy: topsoil for future generations.
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