I’ve noticed something about gardening. You set out to do one thing and pretty soon you’re doing something else, which leads to some other thing, and so on. By the end of the day, you look at the shovel stuck in the half-dug rose bed and wonder what on earth you’ve been doing.
Anne Raven Deep in the Green (1995)
Wood ash is a traditional fertiliser but comes with warnings. The ash from your household fires is fine to use as long as you never burn plastics, polystyrene or tanalised timber in your fire. If you have a very efficient modern wood burner which doesn’t leave much ash, what it does leave will be heavily concentrated. Wood ash is alkaline (so acid loving plants won’t like it and if you add too much to your compost heap, it can alter the pH balance). It has good levels of phosphorus and is high in potassium but has no nitrogen. If in doubt, weigh 200 grams in a plastic bag and sprinkle that over a square metre. That will give you a rule of thumb for a light application. Near enough is good enough – it won’t matter if you up the rate. It seems a pity to waste a natural fertiliser when you can use it spread over lawns and garden, especially the vegetable garden, and get a bonus from your firewood.
Published in the Waikato Times and reprinted here with their permission.