Question: is charcoal ash good for plants?
Answer: Fertiliser: Ash from additive-free wood charcoal contains a lot of potash (potassium carbonate) which is nutritious for many plants. Potash can change the pH of your soil making it more alkaline, so be cautious with its use. ... Deter Pests: Some gardeners use charcoal ash as part of a home made pest deterrent spray.