are wood ashes acidic or basic?
Wood ashes from the fireplace or wood stove may be used to supply both calcium and potassium to soil. The pH level of soil is measured on a scale of 0 to 14, with 7.0 being neutral. Target pH for growing a garden is 6.5 (slightly acidic). Wood ash works best if the soil pH level is somewhat acidic, below 6.5.