How do I control dandelions and other broadleaf weeds in my lawn?

FAQ
Question: 

How do I control dandelions and other broadleaf weeds in my lawn?

Answer: 

In small areas, some weeds can be controlled by pulling and digging.  This method is best accomplished after a soaking rain or deep watering.  Unfortunately, pulling and digging is often ineffective on deep-rooted weeds. 

In many situations, herbicides are the only practical method of weed control.  Effective broadleaf herbicides include 2,4-D, MCPP, MCPA, dicamba, triclopyr, and others.  The most effective broadleaf herbicide products contain a mixture of 2 or 3 herbicides as no single compound will control all broadleaf weeds.  Fall (mid-September to early November) is the best time to apply broadleaf herbicides in Iowa.  Broadleaf herbicides can be applied as liquids or granules.