Things You'll Need
If you are looking for a pre-emergent weed killer for your lawn and garden, then look no further than your home. With a few products straight from the kitchen, you can try to prevent weeds, such as crabgrass and dandelions, from growing before they even germinate. After weeds sprout, kill them with another kind of homemade weed killer, such as undiluted white vinegar sprayed directly onto the foliage.
Mix one part salt and two parts water in a spray bottle and soak the soil with it. You can also sprinkle salt over the soil and water it in. Reapply every week from late winter until after the last frost. Salt will create a soil bed unsuitable for weeds to grow. Note, however, that this makes everything difficult to grow so apply in areas where nothing else grows, such as between the cracks of a driveway or sidewalk.
Pour a pot of boiling water over the area just before and after the last frost of the spring. This will scorch the weed seeds so they don't grow. Boiling water can kill all vegetation so, as with the salt, apply in areas where nothing else grows.
Sprinkle cornmeal in the garden in early spring, at a rate of two pounds per 100 square feet. You can apply it directly on a lawn or garden bed without harming established grass or flowers, but wait six weeks after seeding or two weeks after transplanting. Repeat cornmeal applications in the mid-summer and early fall. Cornmeal is not as effective as corn gluten meal, which is a natural product sold in nurseries or farm supply stores.