Symptoms

• Symptoms of a slug infestation are easy to spot. Slugs (and snails) chew on foliage, causing unsightly holes in leaves followed by a long, shiny trail of slime. They tend to come out to feed at night and in the early morning.
  
  

Treatment

• Slugs are best removed by hand, although they also may be killed with a commercial slug bait. You only need to protect the plant until it has grown to be about a foot tall.
  
  

Prevention

• Slugs often congregate under upside down pots or leaf and flower debris in order to hide from the sun. Prevent slugs from infesting dahlias by removing potential places for the pests to hide.