Devon Ferguson
Published by Devon Ferguson
Last Updated On: March 1, 2023

There’s nothing better than lighting up the grill on a summer's day, cooking up some good ol’ barbeque food for some friends and family.

That being said, disposing of the charcoal ashes afterward can be an absolute headache.

The last thing anyone wants is to create a bin fire. Or even worse, setting fire to the trash collection truck doing their weekly rounds.

Luckily for you, we’ve gone ahead and put together a guide to safely disposing of your charcoal waste, as well as some handy tips and tricks to recycle used and unused charcoal.

Before Cooking

Charcoal top view

Before you go ahead and flame up your grill to cook up some food, there are a few things you can do to get the most out of your used charcoal.

  • Stick to using untreated charcoal on your grill, as this ash can be used in your garden. Treated types of charcoal - often referred to as easy to light - is usually full of toxic chemicals such as borax, that will only harm your soil. The only thing you can do with treated charcoal is throw it away.
  • To reduce your waste, don't overfill your grill. Depending on your charcoal grill depends on how many charcoal pieces are recommended. Typically, a 5cm layer of charcoal will be enough.
  • Always keep a fire extinguisher or bucket of water handy to put out any potential grease fires - your grill can be unpredictable.

Always Extinguish Used Charcoal

You’ll always want to make sure to put out a charcoal grill completely before you go ahead and do anything else. First, close the lid on your charcoal grill, and then close all of the vents to cut off the air supply to the fire and smoke.

If you dispose of the ash too quickly, you may start a bin fire. Therefore, leaving your used coals to cool off for 48 hours is advised.

Disposing of Your Charcoal Ash

If you’ve used treated charcoal or have nowhere to recycle your leftover ash, you’re going to want to safely dispose of the ash in a few simple steps.

Wrapping your loose ash inside aluminum foil is the best way to do this. Once it’s all wrapped up, you can simply throw it away inside a non-combustible container and close the lid [1].

Then, all you have to do is put your garbage bin out as usual, and it’ll be picked up via your usual waste disposal method.

“Allow coals and ash to cool for 48 hours, or pour water onto them and stir carefully to speed up the process. Do not attempt to dispose of them until they have fully cooled.”

- Recyclist

If you want to make the most out of your used charcoal and you’re looking to help out the environment on your way, recycling is the way to go.

Be sure to pick up charcoal without any extra additives next time, and you’ll be able to do just that.

Repurposing Charcoal Ash

Top view of a hot charcoal grill

There are a handful of methods you can follow to reuse your used charcoal briquettes, and surprisingly enough, you’re not only limited to using them in your garden!


One of the most popular ways to reuse charcoal is to turn them into fertilizer. All you need is a garden and a bunch of hardwood charcoal that is untreated.

Loose ash works so well as a fertilizer because it contains something called potash (Potassium Carbonate.) This provides your plants with nutrition, as well as increases the pH levels of your soil [2].

Many flower enthusiasts and experts already know that adding crushed briquettes to your soil can increase the alkalinity and is a good nutrient.

However, it's always advisable to reuse charcoal in moderation, especially if you’re growing plants that require certain pH levels.

If you have a garden full of blueberries, azaleas, hydrangeas, or similar plants, you should avoid this fertilizer altogether. It is also advised not to use ash on seeds or seedlings.

Deter Pests

Extinguished charcoal ashes on the floor

If you’re struggling with a pest problem in your yard, you can use burnt briquettes from your grill to help get rid of them.

Simply grab an ounce of wood charcoal ash, one ounce of hydrated lime, and one gallon of water and mix them all together. This will keep pests such as beetles off your property.

This concoction is also super helpful to farmers, as it can deter mites and lice that bother their chickens by spraying this around their chicken coops.

Control Algae

If you have a pond in your backyard, you’ll be happy to know you can utilize your burnt coals. If you’re not careful, algae can take over your pond and cause a handful of problems.

Thanks to hot charcoal ash, you can make managing this algae much easier. To do so, use one tablespoon of wood charcoal ash for every 1000 gallons of pond water.

Lye Soap

Using wood charcoal, you can make up a few batches of lye soap. You can use lye soap for a whole range of things such as shining up any silver you have laying around the house. A quick search online will provide you with a few helpful recipes.

Recycling Unused Charcoal

Unused charcoal close up image

If you have leftover unused charcoal for whatever reason - may it be the end of grilling season and you have half a bag left - using these coals instead of throwing them away will be much more beneficial to you and the environment.

Diminish Bad Odors

Unused grilling charcoal briquettes can actually be put to use inside of your refrigerator.

Believe it or not, lump charcoal can effectively get rid of bad odors in places like your fridge and freezer, as well as your shoes and cupboards.

Turning It Into Compost

A small compost for plants made out of charcoal ash

Transforming your old grilling charcoal into compost can be a great way of reusing coals.

One of the benefits of doing so is increasing the carbon content inside your compost pile.

It’ll only take one or two pieces of charcoal to improve your carbon content, so don’t worry about wasting too many.

Once the carbon is increased, organic matter will be broken down easier thanks to the energy provided to the microorganisms.

Preserving Cut Flowers

Placing one piece of grilling charcoal under the cut stems at the bottom of your flower vase can prolong the life of flowers.

If the charcoal floats, use seashells or glass marbles to weigh them down. Make sure you change the water every 4 or 5 days.

Reduce Rust

Charcoal ingredients naturally absorb moisture. Grab a sock or a mesh bag, pop one or two pieces of grilling charcoal inside, and put it in your toolbox to prevent rust on tools.

Suppressing Weeds

Unused grilling charcoal can be crushed up and used to suppress the growth of weeds. Not only will this help your plants, but it’ll also make your gardening life much easier.

What Should You do With Ash?

Recycle your ash and not only are you helping the environment, but you’re also saving yourself money on things you’d otherwise need to purchase.

As long as you take the proper care to ensure your charcoals are completely extinguished, the options to put that ash to good use are endless.

Remember, always use wood charcoal without any added additives if you’re looking to repurpose your grilling charcoals. If you know any grillers with extra coal, go ahead and pass this article along.


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