Many organic matters make good fertilizer, but is it ok to use firewood ashes to fertilize your garden? You may be wondering if ashes will hurt your garden rather than help it. If you want to know if firewood ash makes good fertilizer, you are in the right place.
The answer is yes. You can use wood ash as fertilizer. Since wood ash has lime and potassium, it can make an excellent fertilizer. Some firewood ash can provide trace elements to your plants that help them thrive.
However, composting ashes is not always a good idea. This article discusses when and how to use firewood ash as fertilizer.
Should I Use Firewood Ash as Fertilizer?
Firewood ash contains high levels of lime and potassium, so it can be a good idea to use firewood ash as fertilizer in some cases. Potassium regulates plants’ water balance and helps them transport food and create sugar and starches. If plants do not get enough potassium, they are more vulnerable to drought, pests, diseases, and frosts.
Wood ash contains many other essential nutrients such as calcium and magnesium, which can benefit your plants if appropriately fertilized. The nutrients found in wood ash depend on what type of tree was burned.
In conjunction with firewood ash, we also recommend using a smart-release plant food like this one. It works especially well on vegetable gardens and is a must-have.
What Is the Best Way to Use Firewood Ash as Fertilizer?
You should lightly scatter firewood ash over your garden. For the best results, you can have it compost for a while before you spread it around. Firewood ash should be used sparingly in a garden. Too much will harm your plants, so you should spread it thinly over lawns or stir some into your compost pile.
The reason you want to compost your firewood ash first is because wood ash produces lye and salts. Lye and salts are not a big problem in small amounts, but it can burn your plants when there is too much. Composting your firewood ash helps reduce lye and salt.
Firewood ash raises the pH levels of your soil, making it more acidic. If your soil’s pH level is 6.5 or above, you should not add ash as fertilizer. If your soil’s pH is too low, you can use wood ash as a pH source by adding it to your garden three to six months before you plant.
Putting firewood ash in your compost pile will keep the pH level neutral. A good way to do this is to sprinkle the firewood ash over your compost after each layer of compost you add.
When Should You Not Add Firewood Ash to Your Garden?
You should not add firewood ash to your garden as fertilizer if you are about to seed your garden.
You should also not add firewood ash to your garden if you have acid-loving plants or if your garden’s soil pH level is above 6.5.
Never add wood ash to nitrogen fertilizers such as ammonium sulfate, ammonium nitrate, or urea. When these fertilizers mix with high pH materials, they produce ammonia gas.
Is Any Type of Firewood Ash Ok to Use as Fertilizer?
Not all firewood ash is the same. If you plan to use firewood ash to fertilize your garden, you must be careful about which kind you are using.
The nutrients and minerals are much higher for fireplace ashes made primarily from hardwoods. Hardwood like oak and maple ashes have more nutrients and minerals than softwoods like pine and firs.
Hardwood ash that is high in nutrients and minerals includes oak, maple, sycamore, hickory, ash, walnut, cherry, and apple. These types of hardwood also produce more ash than softwoods.
You should not use fireplace or wood ashes from painted wood, pressure-treated wood, or cardboard because they contain chemicals that can harm your plants. Likewise, charcoal residue from barbecue grills and coal should not be used to fertilize a garden.
Will Firewood Ash Prevent Pests?
Wood ash can be used to prevent pests. The salt in firewood ash kills pests such as snails and slugs.
If you want to use firewood ash for pest control, sprinkle it around the base of your plants. When using wood ash for pest control, don’t let the ash get wet. Getting it wet reduces the salt, so it will not be as effective for pest control. If your firewood ash does get wet, you can sprinkle more dry ash over the base of your plants.
Does Firewood Ash Affect the pH of Soil?
Yes, firewood ash affects the pH levels of soil. You can use firewood ash to raise the pH and lower the acid levels of your soil.
Because wood ash raises the pH of the soil, you should avoid using it on acid-loving plants such as gardenias, azaleas, blueberries, strawberries, rhododendrons, camellias, potatoes, parsley, or holly.
Which Plants Like Wood Ashes?
The plants that thrive with firewood ash fertilizer include chives, garlic, lettuce, leeks, stone-fruit trees, and asparagus.
Is It Possible to Use Too Much Firewood Ash Fertilizer?
Yes, it is possible to use too much firewood ash as fertilizer for your garden. You should regularly test your soil’s pH levels to avoid toxic levels of firewood ash.
Wood-burning stoves provide leftover ash that you can use to fertilize your garden. Firewood ash contains nutrients and minerals that plants need to thrive, so it can be a good idea to mix it in with your soil. However, you should avoid putting wood ash on acid-loving plants.
Adding wood ash to a compost heap can help aid fertility and keep the pH level neutral. Don’t add all of your wood ash at once. This will raise the pH and can affect the bacteria and worms in your compost. Instead, sprinkle some between each layer of compost you add to the pile.
The best type of wood ash to use to fertilize your garden is ash made from burning hardwood. Hardwood contains more nutrients that your plants need compared to softwood. Never fertilize your garden with wood ash from painted wood, pressure-treated wood, or cardboard because they contain chemicals that can harm your plants.