It’s the moment of truth. In the 1980s I was a casual user of Roundup, a popular herbicide that I applied mostly to poison ivy. By spraying or painting the foliage, I could kill the whole plant, roots and all.
In those days, Roundup, though toxic, was considered safe if handled carefully. In the 1990s, when an 80-foot-long bank of poison ivy appeared next to my mailbox, I considered Roundup, but by then more concerns had been voiced about its harm to frogs and fish. To be on the safe side, I decided not to spray the poinson ivy with Roundup. I subscribe to something called the precautionary principle, which means I prefer to avoid using a substance if I am not reasonably sure that it is poses no hazards.
At present, the active chemical in Roundup, glyphosate, is more hotly debated, thanks to the creation of “Roundup-ready” crops, which are engineered to survive glyphosate applications so farmers can weed their fields. A lot of this pesticide is used, and the ill effects ascribed to it include cancer and birth defects in people and infertility in cattle, as well as the development of glyphosate-resistant superweeds. It turns up in human breast milk. It is suspected as the cause of gluten intolerance, due to its use as a desiccant for earlier grain harvests. And it’s not approved for certified organic produce.
How bad is it? I’m not a scientist, and I don’t know. But here’s the funny thing: Whether the Environmental Protection Agency, in its current deliberations about glyphosate, gives it a grade of Pass, Fail or Incomplete will not, in any way, influence the way I garden. That’s because my abstinence from Roundup has taught me that I don’t need it.
Dealing with simple annual weeds is easy. If they’re small, you can disturb them with a skimming hoe on a dry day, and they’ll shrivel. Let them go, and you must pull them, dig them or attack them with a chopping hoe. You can use your favorite mulch — hay, shredded bark, pine needles, grass clippings, landscape fabric, cardboard, newspaper — to prevent emergence.
For weeds that build underground empires, the answer is persistence. No plant will survive if you repeatedly remove its leaves, because it will not be able to photosynthesize and thereby feed its roots. Take the pasture grass and wild blackberries that creep into my garden from the adjoining field. Loosening them with a digging fork, I pull up as much as I can. When bits of root that are left behind sprout, I remove any foliage I see.
If I mow the edge of the field next to my plot, that helps, too. In fact, repeated mowing discourages even monster pests such as Japanese knotweed. I’d shear back the poison ivy if it ever returned, though I’d arm myself with plastic gloves and wash my clothes and shoes thoroughly when done.
It’s tempting to use an herbicide in tight places. Would it hurt anyone to trickle some between the cobblestones in my terrace, where dandelions are hard to remove? There are no fish to harm, although I like to encourage garter snakes, newts and toads. I’ve used plain old vinegar, which comes in gallon plastic jugs, and it works after enough applications. You can also buy horticultural vinegar that is four times as strong but costs more.
My favorite trick, though, is to grow plants that will out-compete the weeds, whether in the vegetable garden or the flower bed. In the terrace it’s a tiny bright green succulent named Sedum acre that creeps along the lines of fine gravel between the stones. It erupts in yellow flowers in early summer, and when I interrupt its journey by removing a dandelion, it soon covers my work without a trace.
Damrosch is author of “The Four Season Farm Gardener’s Cookbook”; her website is www.fourseasonfarm.com.