Dandelions are pervasive lawn weeds that start as clumps of green leaves near the top of the soil. The yellow flowers of dandelions eventually turn into white, fluffy balls that are actually the seeds of the plant. If the dandelion weed is not killed, the seeds will disperse and the number of dandelions will increase the next growing season. The key to killing dandelions but not the grass, is to choose the correct type of herbicide.
Purchase a selective herbicide that contains the chemicals 2, 4-D or MCPP. These herbicides will kill only dandelions and weeds, and have no detrimental effect on grass at all.
Turn the spray nozzle on the herbicide bottle to either the spray or stream position.
Hold the nozzle approximately 6 inches away from the dandelion and thoroughly spray the dandelion flowers and leaves with the herbicide. Repeat the application process with any other dandelions that are growing in the lawn.
Wait seven days and examine the lawn for evidence of dandelions. Retreat any dandelions that are still green and apply herbicide to any newly sprouted dandelions.
Do not use a herbicide that is labelled as "broad-leaf," as these herbicides kill everything it touches. Do not apply herbicide on windy days. Apply herbicide when the temperatures are between 15.6 and 29.4 degrees Celsius.