Find out if wood ash is good for the garden and how to use it effectively to fertilize plants. Helin Loik-Tomson / Getty Images While the ash from wildfires can help nourish new growth, is wood ash good for the garden? Yes, the ashes from your wood-burning fireplace can help improve your garden soil. Wood ash has nutrients plants need, like potassium and phosphorus, so it can be a way to feed...