Nothing spoils a home gardener's mood more than encountering weeds where carefully cultivated flowers or vegetables are blooming. Still, of all the garden nuisances, weeds aren't so bad. Unlike Japanese beetles or deadly plant viruses such as verticillium wilt, weeds can be controlled quite simply by either physical (cultivation), preventive, organic or chemical means.
Cultivating is the term used to describe the different physical and mechanical means of controlling weeds. These include pulling individual weeds up by hand, using a hoe or till to chop them up, or mowing them down. Although the results are immediate, there are some drawbacks to these methods. The use of garden tools, especially those with sharp blades, can damage the bark of nearby woody plants, causing wounds that leave those plants vulnerable to diseases or fungi. In addition, overworking the soil can damage the quality of the soil over time. Finally, these methods are temporary and can easily leave parts of the weed (including the roots and seeds) in the soil, where they may sprout and grow anew.
Prevent weeds from growing in the first place by smothering or solarizing the seeds so that they don't have a chance to germinate. A layer of black plastic, tightly secured to the ground with rocks or by covering the edges with dirt, can prevent weeds from growing. Not only does the plastic provide a physical barrier to growth, but the heat generated under the plastic can solarize, or kill, germinating seeds. Cover the black plastic with several inches of high-quality, clean topsoil, and you can plant new plants on top of the plastic.
Many mulches can also prevent weed growth. A thick (3- or 4-inch) layer of wood or plastic mulch is decorative and stifles germinating or sprouting weeds, according to information published by Ohio State University. Avoid letting the mulch touch the stems of plants, however, as this can lead to fungal growth. Many wood mulches host dormant fungi, and the moist environment (mulch seals in moisture in the soil) can encourage the fungi to awaken and multiply. Established weeds will not be stopped by mulch and should be removed before the mulch is laid down.
Chemical and Organic Means
Chemical remedies for controlling weeds are popular with homeowners who want rapid and permanent results. There are many products on the market that will kill weeds. Unfortunately, these products contain poisons that cannot differentiate between weeds and desirable plants. Therefore, when applying these chemicals, home gardeners should take care to protect nearby desirable plants from being poisoned by covering them with plastic or surrounding them with a cardboard barrier, and by spraying on a day that is without any wind. Some organic sprays will also kill weeds as well as your prized perennials, but the advantage of organic sprays over chemical sprays is that organic compounds (such as pelargonic acid) will not add toxins to the soil in your garden.
If you wish to kill the weeds without pulling them or spraying them, you can purchase a weed torch, a tool that allows you to burn the weeds right out of the ground. It takes a couple of tries to get the job done, according to information published by North Coast Gardening, but there is no stripping of the soil or chemicals used.