Good point. Wood ash can indeed have an alkaline effect on soil Ph. I didnÃ¢â‚¬â„¢t bother mentioning it because in order to change your soilÃ¢â‚¬â„¢s Ph level a whole point or more with wood ash you need to incorporate roughly one pound of ash to every ten sq. ft. of soil. This is typically done in the fall so the ash has adequate time to acclimate. As long as you donÃ¢â‚¬â„¢t heap mounds of ash around your plants it shouldnÃ¢â‚¬â„¢t affect your PH. A small ring around each plant, two fingers wide, should be plenty to turn the slugs away.
IÃ¢â‚¬â„¢ve heard saucers of grape juice, or even beer, placed around your garden works well to attract slugs away from your plants. Check them in the middle of the night and gather up the slugs and relocate them away from your garden. IÃ¢â‚¬â„¢ve never tried this, but itÃ¢â‚¬â„¢s another more natural option to consider.