Is Wood Ash Good for Plants?
07.09.2024 - 22:06
/ treehugger.com
Your soil may not need it, your plants may not want it, and it's possible to use it incorrectly. But when properly applied, wood ash can be good for plants. This guide explains how to add wood ash to your garden for optimal plant growth.
Before adding anything to your soil, get a soil test from your county extension office or university extension service to determine your soil needs.
Wood ash is high in calcium carbonate (lime), great for reducing soil acidity. It's an excellent substitute for commercial lime, which has a high carbon footprint. Soils in heavy-rain areas tend to be more acidic than soils in dry regions, so wood ash could be a good garden additive in rainy regions. But, if you conduct a pH test and determine your soil is too alkaline, skip the wood ash.
Wood ash can help with soil structure and porosity, allowing water to reach roots more easily. Take a fistful of moistened garden soil and give it the squeeze test. If it immediately falls apart, your soil is too sandy. If it makes a solid ball, it's too clayey. Wood ash can help to break up clay soil.
Healthy soil is rich in carbon, and wood ash returns organic carbon to the soil. This means wood ash also plays a role in carbon sequestration—not a large one at the scale of a backyard garden, but every bit helps.
Beyond calcium, wood ash also contains potassium, phosphorus, magnesium, and trace amounts of other elements, all of which are essential nutrients plants need.
Potassium, calcium, and magnesium are extremely water-soluble, so their effect on the soil is quicker than other elements. Wood ash is missing significant amounts of nitrogen, however. Adding human urine makes it a nearly complete fertilizer.
Wood ash has proven effective in