Spraying weeds with powerful herbicides like Roundup get the job done quickly, but at great cost to the environment and your health. Roundup contains glyphosate, a chemical that has been linked to non-Hodgkin's lymphoma and infertility, as well as other inert ingredients that are especially harmful to aquatic wildlife. Chemical herbicides often leave residue in the soil and on plants that can damage their growth and poison people who eat and touch them. Before spraying Roundup on your lawn or garden, consider some healthier alternatives.
Pulling By Hand
In many cases, it's possible to remove weeds by hand. If you're able to keep on top of weed flushes, regularly removing the plants reduces future growth. It's easiest to get weeds out of the ground when they're small and the soil is wet. Weeds with long taproots usually need to be dug out since they will grow back from the remaining piece of root. Clumps of weeds that propagate by rhizomes, such as mint and grass, can be removed by getting a digging fork under the clump and pulling up the network of runners. A tool like a hula hoe (also called a stirrup hoe) is easier on your back for getting under the roots of annual weeds without accidentally replanting their seeds. After you've pulled up the weeds, let them dry out in the sun and don't dispose of them in the compost pile or you risk spreading the seeds with your compost.
Some gardeners aren't able to pull out weeds by hand, and sometimes weeds are established in places where it's impossible to get them out by the roots, such as between pavers or landscaping rocks. For these kinds of weeds, garden stores sell small, portable propane or paraffin flamers. These produce an intensely hot focused flame that burns weeds and doesn't damage nearby plants when used carefully. Garden torches have the added advantage of burning nearby seeds as well, and they don't leave any lasting damage to the soil.
Artificial and natural groundcovers are an effective form of weed control, especially in large areas with established weeds. Cut down tall weeds with a mower or scythe, then cover the area with an opaque plastic tarp or landscaping fabric. The weeds and many of the seeds will die from the sun's heat, and lack of light and oxygen. To suppress weeds in a planted area, put down a 3-inch layer of mulch around your plants. You can also control weeds by using winter cover crops such as ryegrass or crimson clover, which out-compete weeds over the winter, or planting native grasses and wildflowers to shade out weeds.
Some natural herbicides that are effective on weeds are white vinegar, rock salt or boiling water. All of these are effective on smaller weeds, although there is still a risk of harming desirable plants. White vinegar can be sprayed directly on weed foliage once a day until the weeds are gone, but be careful not to hit nearby plants. These break down quickly, so you don't have to worry about harming the soil. Pouring rock salt and boiling water on weeds effectively kills them, but these are best used on weeds between stones and pavers. Salt renders the soil infertile until it leaches out, and boiling water can damage roots of nearby plants.