Question
What is the best way to combat Ground Ivy like Creeping Charlie. Dry fertilizer or spraying a liquid style?

Answer
Chris:

Creeping Chrlie is a worthy foe.  I would stay with liquid herbicides for this.  The offer better leaf coverage.  Banvel is recommended.

Cautions about Banvel:
1.  applications must be regular and continuous throughout year to gain control.
2.  do not apply in grass dormancy - summer and winter.
3.  mow grass high - 2.5 to 3.0 inches.
4.  favor the lawn with cultural practices, mowing, fertilization, aeration, etc.

SORRY, I FORGOT TO INCLUDE AN ALTERNATIVE ANSWER:
BORAX (TWENTY MULE TEAM BORAX) APPLIED EXACTLY AS PRESCRIBED APPARENTLY ALSO WORKS.  TRY THIS URL FROM U. of MINNESOTA FOR DETAILS:
http://www.extension.umn.edu/info-u/plants/BG522.html

I hope this helps.  Best wishes.