Weeds are the bane of any garden. No matter the species, weeds are not only unsightly, but they also compromise the health of plants in the garden. Weeds are invasive plants that compete with surrounding plants for root space and sun exposure. Existing plants suffer dehydration because weeds absorb some of the moisture from the soil and tall weeds prevent shorter plants from receiving adequate sunlight.
Post-emergent Weed Killer
Post-emergent weed killers work on weeds that have germinated from their seeds. These are readily available in nurseries or in the gardening department of most big-box stores. Bottles of post-emergent weed killer generally indicate what variety of weeds they kill. If you're unsure what type of weeds you have, pluck out a sample and take it to a local nursery to inquire which post-emergent herbicide will kill that variety of weed. Apply post-emergent weed killer according to the packaging instructions. Most are applied with spray, while some use a swab to apply directly to the leaves.
Pre-emergent Weed Killer
Pre-emergent weed killers prevent weed seeds from germinating. To be effective, these types of herbicides must be applied before the seeds have sprouted. To know which type of herbicide you need to use, plan ahead and know what areas of the garden tend to sprout what kinds of weeds each year. Application is typically in the form of a powder or spray bottle, preferably during the winter and summer dormant phases (before the weeds usually germinate and sprout).
White vinegar is an eco-friendly alternative to toxic, commercially available weed killers. The natural acid in vinegar kills the weeds by destroying the leaves and stems. EdibleContainerGardening.com suggests spraying full-strength white vinegar directly onto the weeds' leaves. Thin-leafed weeds, such as clover, begin to wilt soon after application.
Boiling water is an eco-friendly form of pre-emergent weed killer. This method is as simple as putting a pot of water to boil and carrying it outdoors. Be warned, however, as boiling water should only be used to kill weeds in otherwise bare gardens. Any desirable plants in the garden are also killed by the scorching temperatures of the boiling water. Once the weeds are killed off and the soil has cooled, the area is safe for your plants.
Newspaper or Cardboard
Layers of newspaper or corrugated cardboard kill weeds in the garden by preventing them from getting sunlight. This method effectively kills and prevents weeds for several seasons. The paper or cardboard can be covered with mulch or additional soil to make the garden more aesthetically pleasing.