Thursday, May 24, 2012

Wallflowers they are not

kw: book reviews, nonfiction, natural history, plants, weeds

Many years ago, I was doing a bit of gardening when my cousin and her husband came by. On the way in I told them I was transplanting a couple of Oxalis plants from the lawn into a corner of a flower bed. "Oxalis!" the husband sniffed, "Get rid of it. That's a noxious weed!" I refrained from pointing out that, among some 800 species of Oxalis, we find the Shamrock and a number of other species that are valued for rock gardens. The common California species have attractive trefoil foliage year-round (in Pasadena anyway), and small, pretty yellow flowers once the rainy season gets going.

My mother was a reader, more than a TV watcher, and I've followed her footsteps. One series of adventure novels she relished features a hero called the Scarlet Pimpernel. This name would be sniggered at today. As it happens, the pimpernels, scarlet, blue, and a few other colors, are familiar roadside weeds in England, though rarely found in the Americas.

We have a hedge about our yard, so I don't use "weed and feed" or other chemical-warfare methods to control non-grass plants in my lawn. It would harm the privet plants. As a result, we have an interesting variety of ground covers, forbs and other species in the turf. Wild strawberry, with its creeping habit, is pretty in a corner or two, but we pull it from the middle of the yard. There are other plants we try to stay ahead of. We have a scattering of wild violets, which I really like, but my wife insists on digging them out. I do my passive-aggressive thing about that, and just ignore them, pulling other weeds instead.

It was with great delight, then, that I read Richard Mabey's lovely book Weeds: In Defense of Nature's Most Unloved Plants. While discussing the general concepts of native plants, wanted or unwanted, he has structured his book with a round dozen chapters, each based on a particular plant or family of plants, including the infamous (and imaginary) Triffids, from John Wyndham's 1951 novel The Day of the Triffids.

Really, though, what is a weed? Simply put, it is a plant that thrives in a place you'd rather it wasn't. Our next-door neighbor has a bird feeder. She uses uncooked birdseed, so below the feeder various plants are constantly popping up, most notably Millet, also known as Sorghum, a fast-growing, aggressive, tall grassy plant. Of course, she regularly rips everything out except the few wisps of lawn grass that survive the onslaught. When we lived in South Dakota, a farmer's field across the road was used to grow Millet every year. In 1984 a tornado zipped through the field, scattering stuff over the whole neighborhood. The following year, everyone had Millet growing in their yards. We didn't mind. We knew our rocky soil had low fertility and the grass would soon crowd it out. It did. But if the tornado had run through my flower bed and blown some poppy seeds into the Millet field, the farmer would likely have hoed them out once they grew.

There were no weeds before there was agriculture. There is no thought of a plant being out of place when you have no concept that certain plants "belong" in certain places. Now, many standard practices of "modern" agriculture are found wanting. Many years ago, at Malabar Farm in Ohio, it was found that growing a clover or alfalfa crop among the corn in a cornfield was more effective weed control than blasting everything with pre-emergents, post-emergents, and targeted glyphosate sprays. Also, the legume fertilized the corn. Few have picked up on the Malabar Farm experience, but a few farmers have begun to re-learn this lesson. And clover isn't just good for corn. The healthiest looking yard in our neighborhood is full of white clover (just like the yard was where I grew up half a century ago). I'm encouraging the clover patches in my yard. They reduce the need for fertilizer, and squeeze out some of the weeds we've been hand-pulling.

Mabey discusses an interesting matter: Many English plants have been brought to North America and become invasive weeds. Very few American plants have successfully made the reverse migration. He attributes this to the historical fact of Europe's high population density. While there were a great many more Native Americans prior to 1492 as compared to the number in the 1600s once smallpox and measles had killed 95% of them, the population density was always lower than that of Europe and England for at least 1,500 years. Intensive agriculture has caused the English native plants, which are now quite different from those of pre-Roman times, to be adapted to frequent disturbance, primarily by weeding practices. By contrast, pre-Columbian agriculture in the Americas was based on using fire as a "pre-emergent herbicide", but pretty much leaving a field alone once a crop was established. Thus, English plants have a long history of resisting the hoe. American plants don't.

Many of the stories in Weeds recount the author's wanderings and observations of native plants all over England. Some grow quickly and set seed almost before you find out they are there. Some grow best in cracks in stone walls, and have, for example, traveled along walled roadways, even throughout the storied universities of London and Cambridge. He tells of a study done a century or more ago, that found more than 360 plants growing in, around and over the Roman Coliseum, until they were assiduously removed by the Garibaldi administration. I suspect if the old place were left alone for a few decades, most would return.

Throughout the book, the plants are referred to by vernacular names, and there is a glossary in the back, nine pages worth (!), to document the binomial names. I find myself chagrined that I know only a couple of dozen native plant names; Mabey knows hundreds. But I do enjoy seeing the various plants in their seasons. I still like having some Oxalis around. The East Coast species differ from those I knew in California, but are just as pretty. As the seasons pass, one after another, the native plants, and their English companions, provide a backdrop or frame to the more cultivated flower beds in my neighborhood. I am glad there is movement afoot to recognize the value of some of the plants that we've been conditioned to destroy on sight. I hope Weeds is but the vanguard of a movement towards a more rational and measured response to the plants that insist on making themselves our companions.

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