Dre Campbell Farm
Wood Ash in Garden: 11 Practical Uses

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Wood Ash in Garden: 11 Practical Uses

Those lucky enough to have a wood stove may find themselves stymied when it comes to the wood ash they continuously clean from the fire pit .

There is an alternate use for everything, and wood ash is no exception. One of the places it is most versatile is the garden.

What is Wood Ash?

Wood ash is the inorganic and organic powder residue that remains after the combustion of wood. Along with wood-burning stoves, the other main source of fire pit ashes is from industrial power plants that often burn wood to make electricity.

Although wood is not burnt in every home as a heat source anymore, it is an excellent raw resource that boasts a variety of uses and benefits around the home.

The average cord of wood is four feet wide, four feet tall, and eight feet long.

Depending on the type of wood being burnt (the quality and whether it is hard or softwood), this works out to approximately 1%-2% returned to you in the form of wood ashes.

If you don’t burn wood for home heating purposes, making an outdoor pile of dry wood and then burning it is all it takes to get your stack of ashes.

Are Fire Pit Ashes Good for Your Garden?

Absolutely! Instead of looking for areas to dispose of it safely, consider these 11 practical uses for it in the garden.

1. Wood Ash Fertilizer

Plants need a variety of essential nutrients to thrive and grow. Most of them can be found within wood ash.

Early spring is the best time to till collected wood ash into the garden, preferably when the soil is dry and plant life has not started to grow.

The secret is making sure the wood ash is tilled in well. If not, certain areas will have too much salt, and others not enough.

As a rule, for a 1000 square foot garden, you will require about 20 pounds of wood ash fertilizer.

2. Wood Ash in Compost

Looking for gardens worthy of a magazine spread, of high yields and prize-winning veggies?

A healthy compost pile is what gardeners look towards, and the addition of small amounts of fire pit ash will make a marked difference in this garden staple.

The smell of the ash also becomes a deterrent to wildlife like bears who would otherwise consider the compost pile a free buffet.

Check the middle of the compost pile before adding wood ash and again a month later. You should find the center contains greater numbers of worms and insects working hard.

3. Lime Substitute

Lime is used agriculturally for its nutrient value, and to raise soil ph. Instead of paying for lime at the farm supply store, make good use of your wood ashes instead.

The largest portion of the chemical makeup of wood ash is calcium carbonate or lime. This garden savior mineral makes up roughly 25% of ashes.

4. Slug Repellant

Insects like snails and slugs move around underground with greater ease when the soil contains more moisture.

When the slime and fluid allowing them to easily navigate surfaces is absorbed, it makes free movement difficult.

Wood ash will soak up moisture when applied to a damp surface, so the theory is that slugs and snails will be repelled from plants and soil treated with ashes. They’ll have to look somewhere else for their next meal.

5. Raises Soil pH Levels

The magic happens thanks to the oxides and carbonates left behind when wood burns and these combine to neutralize acidic soil. Except for gasses lost while burning, such as sulfur and nitrogen, wood ash still enjoys all the elements present in actual wood.

The type of wood does matter. Softwoods do not contain high levels of much-needed calcium and potassium, while hardwoods boast large amounts of these minerals.

You will need to replace the ash after heavy rain, however, as it tends to leach out the good stuff whenever it rains.

This also means that valuable nutrients needed to raise ph. tend to get into the ground faster than with other options, like limestone.

6. Prevents Blossom End Rot

This condition occurs most frequently when the start of the growing season is very wet and then becomes extremely dry. It’s really an indicator of soil issues.

It will be observed while fruits are still green or when ripening begins and often shows on crops like tomatoes, cucumbers, peppers, and other fruit crops.

Plants with visible signs of blossom end rot require higher levels of calcium to prevent the problem from recurring, so mixing in wood ash after soil testing could be beneficial.

7. Prevent Frost Damage

Certain crops are not ready for harvest until the time is getting close for frost. Depending on the area you live in, early frosts may be a concern.

If you want to protect your plants and give them the additional time they need to mature, try applying a light dusting of wood ash over them.

Plants freeze and die because their water content raises the freezing point. Using ashes that is chock full of mineral salts lowers the freezing point without causing additional damage to the plant’s tissues.

8. Dust Bathe Chickens

Anyone with chickens knows just how much they enjoy taking a bath in the dust. It is their only way of keeping clean, meaning they also require dust.

You can easily make a bathing box for your chickens and set it inside the coop, or outside where it is protected from the rain. Use either sand or soil and mix in some wood ash.

The smell of the ash will also keep flying insects like mosquitoes away. Parasites like lice, fleas, and mites are likewise deterred because they are suffocated by wood ash.

9. Freshen Up Chicken Coop

Since wood ash is alkaline, when it is sprinkled throughout a chicken coop it assists in neutralizing fecal ammonia odors.

The same principle is applied to baking soda when it is used to keep odors out of refrigerators. It also keeps away many insects that could otherwise be a nuisance.

10. Ant Repellant

Many persons are looking for non-toxic and safe ways to rid their gardens and homes of ants. Wood ash used for ants fits this philosophy perfectly.

Place a thick layer of ashes over the opening to ant hills and near cracks insects use to enter various areas. Check daily to make sure the holes are still covered.

If not, simply reapply. The ants will get tired of digging out their hole daily and will move on to easier quarters.

11. Chicken Feed Supplement

Many farmers or homesteaders add calcium to feed for their flock. While this is usually in the form of oyster shell, there are other options.

A free and natural way to give your chickens more calcium and potassium is to add ashes into their food.

Only a small amount is needed — roughly a 1% ratio. By doing this it is possible that manure smells may be reduced, and that a hen’s laying capabilities are extended longer than normal.

You can also add small amounts of charcoal from the wood ash into chicken waterers. Not only will it filter the water and reduce odors, but it will also impede the growth of bacteria and algae.

Which Plants like Wood Ashes?

Some plants thrive with the addition of wood ashes to the soil, while others do not do well when the ph. of the soil is too high.

Crops like artichokes, cauliflower, chives, and greens like arugula, spinach, lettuce, and collards, like wood ashes. However, acid-loving plants such as strawberries, radishes, rhubarb, blueberries, onions , potatoes, peppers, and parsley will not thank you for your efforts.

Please note, however, where club root disease is present, wood ash can be used to successfully treat any plant with the disease.

When it comes to stunning flower gardens, especially those planted for bees, here are some plants that would not mind a helping hand:

  • Lavender
  • Maltese Cross
  • Phlox
  • Lenten Rose
  • Wild Red Columbine
  • Jacob’s Ladder
  • Clematis
  • Black-eyed Susan
  • Italian Bugloss
  • Foxglove
  • Bearded Iris
  • Autumn Joy

Plants are unable to flourish without certain minerals. When mineral deficiencies exist, plants suffer.

Common signs that your plants are mineral deficient include yellowing and curling of the leaves, stunted growth, and eventual death.

Before adding wood ash to plants or the surrounding soil, purchase an inexpensive soil test kit and check the ph. yourself

Do not use it on rhododendrons, marigolds, nasturtiums, azaleas, and other flowers that thrive well in acidic soil.

If you have any of these plants commonly found in home gardens, save some of your wood ashes just for them.

Nutrients in Wood Ash

Most people would be surprised to learn just how many nutrients are contained within wood ashes. Far from being a waste product that needs disposal, charcoal ash has true value around the home and garden.

When referring to plants, wood ash contains four important and needed minerals. The four main minerals are:

  • Phosphorous
  • Calcium
  • Potassium
  • Magnesium

Some soils naturally lack these minerals in abundance, while others need fortification.

Calcium compounds account for roughly 25% to 40% of wood ash.

Also found in charcoal ash are minerals like potassium (around 4%), sodium, magnesium, aluminum, and phosphorus (around 2% each).

In much smaller amounts you will also find copper, boron, sulfur, zinc, and molybdenum.

While it seems to have a bit of everything, one item it lacks is nitrogen. Areas that have consistently nitrogen-poor soil, a specialty supplement, or fertilizer could be needed.

Even though wood ash is rich in many trace and secondary minerals, geography plays a large part in determining which nutrients your particular type of ash contains.


Find a storage spot to keep your ashes dry during the winter so there is no nutrient loss.

By the time spring arrives, you should have a decent supply set aside to use in and around the garden area. And if you find yourself short on ashes, any number of local people will likely allow you to have theirs for no cost at all.

Sasha Brown

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