I’m a Lonely Little Petunia

How do you keep the weeds down in your flowerbeds, around shrubs and trees, and in sidewalk cracks—without pulling the trigger on a toxic product? Herbicides containing glyphosate—Roundup is one example—used to have the reputation of being safer than other herbicides. However, more and more research links these products to human health risks. And glyphosate is often combined with toxic “inert” ingredients and remains in the soil for months.

Here are some alternatives:

• Mulch. Keeps the weeds down and breaks down to enrich the soil. Use about three inches.
• Gadgets. Some pop weeds out of the ground; others use flames or radiant heat to kill weeds.
• Household vinegar. Like glyphosate-containing herbicides, vinegar browns whatever plants it contacts, so be careful where you apply it. You can use a spray bottle. If you mix in 10 percent liquid soap, the vinegar sticks better to the leaves. Apply it on a hot, sunny day, and coat the leaves well. It does not kill roots, so you may need to reapply it until the weeds’ underground food stores are depleted. It works best when weeds are small.
• Newer, natural herbicides. These are based on ingredients such as acetic acid, citric acid, garlic extract, and citrus oil. As with household vinegar, you may have to reapply regularly until plants’ food stores are used up. You might want to avoid products with high acetic-acid concentrations—you can find concentrations as high as 20 percent—because they can injure eyes and skin. (Household vinegar has an acetic-acid concentration of about 5 percent.)