Digging weeds can be arduous work. If you are gardening organically or are concerned about how your gardening practices affect the environment, you'll be happy to know that there are effective ways to kill weeds without using commercial chemical weed killers. However, before you whip up a batch, keep in mind that homemade eco-friendly weed killers are nonselective; they will kill any plant that they come into contact with. If your sensitive garden plants are very young or growing very close to the weeds in question, digging may still be your best option.
Cut the weeds down to an inch or so above the ground. Repeated cutting on its own will eventually kill even perennial weeds without the need to dig, but it will also prepare them for a number of other control methods.
Boil a pot of water and pour it on the weeds. (If you cut the foliage first, this will reduce the chance of splashing boiling-hot water onto you or nearby desirable plants.) Any plant tissue that the boiling water touches will be cooked to death.
Allow the cut weeds to grow back to a few inches in height. Weeds are more susceptible to herbicidal control when they are actively growing. Spray the weeds with vinegar until the point of runoff. Be sure to coat all of the plant's tissue. For best results, spray on a hot day with no wind and no rain forecast for the next 48 hours.
Spread 12 to 20 pounds of corn gluten meal per 1000 square feet of lawn in your yard. Corn gluten meal acts as a pre-emergent herbicide and suppresses the seed and seedling growth of a number of common lawn weeds. For best results, apply the meal once in spring when the weeds are sprouting and once between mid-august and September. Water the lawn with 1 to 2 inches of water to incorporate the corn gluten meal into the soil, and then allow the top 3 inches of the soil to dry out and remain dry for a few days before watering again. Corn gluten meal makes young plant roots more susceptible to drought.