Only if you need to bring the ph more basic. Test your soil first. If it is really acidic, wood ash can bring that more neutral. You should always test first though. My garden area is right under pine trees and gets needles dropped every year on it. I had thought it would be very acidic. I had planned on mixing in wood ash. I tested first though, mostly on a whim, and found out it was a 7 ph. Not acidic at all. Putting ash on that could've been bad.
