I wanted to learn more about how charcoal ashes affect my plants. I’ve heard old wives tales about using ash in the garden. But, I wanted to know if charcoal ash could truly benefit plants. You can find the results of my research below.
Charcoal ashes are good for plants because they can be used to improve pH levels of the soil, attract beneficial microorganisms, and add nutrients to the soil. You can also use it to get rid of certain harmful pests on your plants.
I’ve written a lot more details about charcoal ashes and their benefits in the post below. You will also find information on how to use the charcoal ash in your garden.
Why Charcoal Ashes Are Good For Plants
Turns out, the old tips and tricks you heard from your grandparents are true. Ash from charcoals can benefit your plants in several ways.
Ash is nothing more than the leftover residue from burning your charcoal. While most people toss it out, ash can serve many different purposes. It’s an excellent source of lime and potassium.
Lime alters the pH level of the soil. Not only that, but it can promote the spread of good bacteria. This ultimately creates a more conducive environment for growth.
Meanwhile, potassium can strengthen plants by thickening the cell walls. Potassium also plays a big role in disease resistance and crop yield. This mineral is so important for plant growth that it’s one of the “Big Three” in commercial fertilizers.
Charcoal ash can do a lot to improve soil quality. However, there is one important caveat. You must use charcoal products that are free of additives and chemicals.
Using the Right Charcoal
You will find many different types of charcoal products on the market. Not all of them are going to work in your garden.
Basic charcoal is a black carbon residue. It’s wood that’s cooked in a low-oxygen environment. This drives out all the moisture to create a fuel source that burns at a very high temperature.
Briquettes are similar to charcoal. But, manufacturers produce it using compressed charcoal dust, wood shavings, or pulp. Any charcoal with a uniform shape is a briquette.
Ash from natural charcoal and briquettes are perfectly fine to use in your garden. The problem comes from treated charcoal products.
Many modern grilling products contain chemical additives. You might see products with lighter fluids and other ingredients that help with the cooking process.
Those are the types of charcoal ash you want to avoid. Even though the charcoal is burnt, you still run the risk of adding those chemicals to your garden.
If you want to use charcoal ash, stick to natural products that don’t contain any chemicals.
How to Use Charcoal Ashes
Charcoal ash is a versatile garden amendment that you can use to address a wide range of needs. Once you gather it from your grill, you can apply it to the soil, use it on your plants, and even toss it in your compost.
Here are some of the most common ways gardeners utilize charcoal ash.
Add to Compost Pile
Charcoal ashes make a wonderful addition to your compost pile. Ash is primarily carbon, which is important for decomposition.
Your compost heap is teeming with microorganisms. There are beneficial bacteria, fungi, and tiny insects. All of those organisms work together to break down carbon-containing organic waste to its simplest form. Once the decomposition process is complete, you’ll have nutrient-rich humus.
Adding charcoal ashes to the mix will only benefit the composting process. The ash will feed the organisms. Think of it as even more organic waste that you can turn into usable compost.
Correct Acidic Soil
If you’re dealing with acidic soil, charcoal ash is a good all-natural amendment. The ash’s trace amounts of potassium and lime make it more alkaline. Adding the alkaline ash will slowly raise the pH balance to neutral levels over time.
The potassium affects chemical reactions deep within the soil. During this process, the pH level rises. Because it happens deep below the surface, it’s at the prime spot for roots to take advantage of the change.
The lime improves soil pH because of its chemical makeup. Lime contains both calcium and magnesium. The two minerals create a more alkaline environment as they break down.
Raising the pH level of your soil takes time. In most cases, the process will not yield noticeable results until after a year or two. But, the change is worth it. High acidity levels affect the way plants absorb nutrients. Neutralizing it will create a garden that’s more conducive to plant growth.
Use for Pest Control
Having issues with garden pests? A generous sprinkling of charcoal ash should take care of that problem in no time. The fine powder pulls moisture from the body of insects.
The lime in charcoal ash also works to suffocate and kill pests. You can apply it dry or mix it up with a gallon of water to use it as a liquid pesticide.
Use as Fertilizer
Those beneficial nutrients and minerals in charcoal ash can benefit your plants directly as a fertilizer. Just apply it like you would any other fertilizer. Sprinkle the ashes around the soil and work it in.
Do be careful about how much you use. As we mentioned earlier, ash will raise the pH level slowly over time. If you have acid-loving plants, you will encounter some growth issues.
Not only that, but you could overload your plant with potassium. This can change the way your plant uses nitrogen. Over time, the plant may experience nitrogen deficiency, which stunts growth and yellows foliage.
Protect Plants from Frost
Here’s a unique benefit you might not have thought of.
The mineral salts in charcoal ash can lower the freezing point of water in the soil. It’s the same scientific principles behind road salts. Dusting the plant leaves with ash and sprinkling some around the base of the plant can prevent frost damage.
It won’t keep them protected in very frigid temperatures. But if the climate is hovering around the freezing point, the charcoal ash can make a world of difference.
Is Wood Ash Good for Plants?
Wood ash is the powdery residue left over after burning a fire in a wood stove or campsite. It looks similar to charcoal ash and is often used interchangeably. But, wood ash is the byproduct of burned hydrocarbons.
It has a slightly different chemical composition and nutrient breakdown.
Either way, it’s also good for your garden. Many would argue that it’s better because you don’t have to worry about any chemical additives.
You can use wood ash the same ways you would charcoal ash. It’s particularly useful as a fertilizer. The nutrient breakdown is approximately 10 percent and 1 percent phosphorus.
Phosphorus is another important nutrient in commercial fertilizers. The nutrient is responsible for converting other nutrients into usable energy. It helps the plant store energy and even assists with photosynthesis.
Like charcoal ash, wood ash works well in the compost. It can also raise the pH level of the soil.
You don’t need a ton of ash to make a difference. Only a small amount can change your garden for the better.
Is Paper Ash Good for Plants?
Ash from the burnt paper is nearly identical to ash from wood. After all, the paper is merely wood pulp and other fibers. You can use it on your plants and achieve many of the same benefits.
However, you do need to be careful about the types of paper you use. Manufacturers use chemicals to improve strength and overall resilience. Bleach and chlorine treatments are common as well to create white paper.
You also have to consider any coatings. For example, glossy papers may feature resins and polymers that you don’t want in your garden. Toxic heavy metals are prevalent in the paper industry, too.
There’s also the matter of ink. Large-scale printers might use inks with a range of chemicals and additives. Most inks from laser and inkjet printers are safe, as they contain natural oils. Newsprints are fine as well. But, you might want to err on the side of caution for paper products with a composition you’re not familiar with.
Here are some of my favorite container gardening tools
Thank you for reading this post. I hope it helps you with your gardening needs. I’ve listed some tools below that can help you with container gardening. These are affiliate links so I’ll earn a commission if you use them.
Gardening Gloves – I find the Pine Tree Tools Bamboo Gardening Gloves really good for both men and women. It’s made from bamboo so helps absorb perspiration. They are also comfortable and fit very well.
Containers – You know picking the right container is crucial for your container gardening. I’ve written a detailed post on the best containers you can choose from. If you’re happy with a plastic container, you can check out the Bloem Saturn Planter.
Watering Can – This is a must-have tool when you’re growing plants in pots or grow bags. It helps to water the potting soil without splashing on the foliage. The Kensington Watering Can is stylish, strong, and can provide precision when watering potted plants.
Trowel – Garden Guru Trowel is my favorite because it’s durable and comfortable to use. My gardening friends really love having a trowel because they use it for digging soil, mixing fertilizer, moving seeds, leveling out the soil, mixing compost or mulch, and also dividing tubers
Bypass Pruner – I really like the Corona Bypass Pruner because it’s durable and gives a clean cut that helps plants recover faster. If you’re looking for something cheap, get the Fiskars Bypass Pruner that is really good as well.
To see an extensive list of the best container gardening tools gardeners recommend, check out this resource that I made for you.
Kevin is the founder of Gardening Mentor, a website that aims to teach people to grow their own food in a limited space. As a self-taught gardener, Kevin has spent several years growing plants and creating gardening content on the website. He is certified in Home Horticulture and Organic Gardening by expert gardeners from Oregon State University.