The best natural weed control starts with prevention. Here's some preventive measures you can take in landscape beds to control and/or prevent weed growth:
Weed Barriers
Perhaps one of the most effective measures that you can take to prevent weeds is landscape fabric. Landscape fabric is available at your local nursery and garden center. It comes in various size rolls - usually 3 feet in width and from 50 to 150 feet in length. Rolls usually run around $10 to $25 depending on the length. If the area you intend to cover is very large, larger rolls can usually be special-ordered, and come at a substancially lower cost.
Make sure the landscape fabric you buy is porous and not plastic. Plastic will suffocate any plants in the bed. Porous fabric will allow nutrients and fertilizers to pass through, as well as allow water to pass through and evaporate.
Cut an "X" in the fabric to easily slip it over small plants. Cut a slit from the side to the center to slip around the trunk of a large tree or shrub.
Mulch
Application of various types of mulch can greatly reduce weed population in landscape beds and islands. A two-inch layer of shredded wood mulch is an excellent way to suppress weed growth. Don't put it too much thicker as this can prevent water from reaching the roots of plants, and fugus can develop in the mulch. Eventually, wood mulches break down into rich organic matter that will beneficial to the plants and trees growing in the landscape bed.
Don't Disturb The Soil!
Weed seeds can lie dormant in the soil for many years. Disturb the soil as little as possible. Cultivating the soil by raking, tilling, or turning it over can uncover dormant seeds and often within days you'll have weeds appearing. Once on the surface, they receive the water and sunlight they need to make them grow. When you dig to plant, make sure to mulch good after planting, leaqving no dirt exposed.
Decapitation
Destroy weeds before they flower and go to seed. When weed flowers are allowed to go to seed, your problem becomes much worse, especially if these weeds are added to your compost. Compost must be hot (140-160 degrees F) to kill the weed seeds, and most home compost operations don't reach these temperatures.
Indecent Exposure
Don't leave areas of bare soil which invite weeds.
Starvation
Use soaker hoses, drip irrigation, watering cans, and container watering systems that only water to plants you want to grow. Apply fertilizer only around the plants you want to fertilize. No need to waste water and fertilizer on weeds you don't want.
Manual Backhoe
Hand pull large, established weeds. Hold the weed by the base of it's stem, and make sure to pull out the whole root. Remulch if soil becomes exposed.
Corn Gluten
As a weed suppressant, corn gluten acts as a natural weed preventer by inhibiting seed germination by drying out a seed as soon as it cracks open to sprout. Problem is, not too many garden centers have begun to carry this product, though it is available through several online sources.
Vinegar
Yes, that stuff in your kitchen cabinet. If weeds are caught while young, they can be effectively killed by spraying them with vinegar. Make sure to spray on a sunny day, and when there will be no rain for a couple days. In case you're wondering what's in vinegar that kills weeds, it's the acetic acid. The higher the percentage of acetic acid in the vinegar, the better it will operate as a natural weed killer, technically speaking. Vinegar used for culinary purposes is relatively low in acetic acid (5%), so repeated applications will be necessary when using it as a natural weed killer. There are stronger vingars available that will be more effective.
