Wood ash is an organic gardening fertilizer but use it carefully and be sure you know your soil pH before using it. If you’re already dealing with alkaline soil, spread the wood ashes outside where they won’t change the soil pH around plants you like or your vegetables. They can raise soil pH rapidly. Wood ashes add potassium, calcium and phosphorous back into the soil – great for tomatoes.
Jeanne Grunert is a certified Virginia Master Gardener and the author of several gardening books. Her garden articles, photographs, and interviews have been featured in The Herb Companion, Virginia Gardener, and Cultivate, the magazine of the National Farm Bureau. She is the founder of The Christian Herbalists group and a popular local lecturer on culinary herbs and herbs for health, raised bed gardening, and horticulture therapy.
Wood ash can be a great help. I’ve had people ask me why they burn rainforests when they’re clearing the land for farming. The answer is that rainforest soil is pretty baren of nutrients – it’s all up in the canopies of trees. There is so much forestation that the plants have sucked up much of the available nutrients. Burning the forest creates the ash, and that is easily plowed back into the soil, creating fertile soil for growing crops. Plant and Garden Blog
Interesting Ann and thanks for leaving a comment. I thought the rainforests were burned because it was easier than clearing away timber, except for special hardwoods like mahogany that can be sold. But adding the ash back into the soil makes sense.
Wood Ash really is great for tomatoes and in this part of Virginia the soil wants to go back to acid really quickly so adding wood ash can be great. In the many years we have raised tomatoes one year stands out as having the absolute best tasting tomatoes and that was 1998. (Sounds like wine doesn’t it!) We had put wood ashes out on our garden spot and our pH was up pretty high (closer to 7) in that area. I am convinced that the higher pH helped create those great tasting tomatoes. Was not a year with excess rain so some watering was necessary and that may have helped too. We did soil samples that year and VA Tech’s soils lab said pH too high for vegetables. I just laughed. I have in the years since then seen many sources that say tomatoes like the soil a little closer to neutral than some other things. Never have trouble with blossom end rot either.
Enjoy your blog.
Liz
Hi Liz, yes in our part of Virginia too, we need to do anything and everything to raise the soil pH. When I had ours tested before we moved in the pH was around 4. The lab actually called me to ask where the heck the soil was from (the lab was in NY where we lived). They had never seen soil like it thanks to all the pines grown here which just turned the soil to acid. Wood ash is great to raise pH quickly.