Most homeowners' efforts to rid their gardens of dandelions depend almost exclusively on commercially available chemical herbicides. Such herbicides have a lethal effect only on the fully mature dandelion, but not on the seedlings of the plant, which at any given time outnumber the mature plants nearly twenty to one.
If one wished to rid one's garden completely of dandelions using only commercially available herbicides, one would most need to know the answer to which one of the following questions?