There are so many different types of weeds it is hard to know which ones are invading your lawn. If you see yellow flowers on your weeds, you may have butterweeds, or yellow clovers. They could even be dandelions. The good news is that most weed killers on the market are able to kill hundreds of species of weeds. To kill your weeds with yellow flowers, you must apply your weed killer correctly.
Put on a pair of garden gloves and pull the weeds with the yellow flowers out. This will work if you don't have a large amount of this type of weed. A few small patches shouldn't take too much time to remove.
Wet your lawn several hours before you plan on using a granular herbicide. This is necessary for the weed killer to be as effective as possible.
Measure the area where you see the yellow-flowered weeds. You will need to read the product label of the particular granular herbicide you decide to use to find out how much herbicide to apply per square feet of lawn. This could be between 2 lbs. and 8 lbs. per 1,000 square feet of lawn.
Shake the granular herbicide over your patches of weeds based on the measurements you took in Step 3. Make sure you wear gloves. It is not safe to handle the herbicide with your bare hands.
Keep your children and pets indoors until the ground has dried.