Is Wood Ash Beneficial For Your Tomato Plants? How To Use It?

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In Brief: Is Wood Ash Beneficial For Tomato Plants?

Wood ash is rich in nutrients that may be beneficial for tomato plants. It may increase the fertility of the soil and raise the soil pH or be added to the compost piles to maintain its neutral condition. Also, it may repel the garden pests, including the slugs and snails. The dried ash may be sprinkled around the tomato plants for good results.

In this article, l will discuss if wood ash is beneficial for tomato plants and how to use them in the soil.

I have had success with using wood ash for my tomato plants. I have added my experience, the insights of other fellow gardeners, and research papers in this article.

Keep reading to know more about the benefits of adding wood ash to tomato plants.

Benefits Of Adding Wood Ash To Tomato Plants

Wood ash is rich in nutrients that are beneficial for tomato plants. It may help in the growth of tomato plants and reduce the incidence of diseases.

My tomato plants grow well with wood ashes.

Wood ash is a residue obtained from burning wood. It has high contents of potassium, phosphorus, calcium, and magnesium.

So, instead of dumping them into landfills, they may be used for fertilizing the gardens.

The different benefits of adding wood ash are discussed below.

1. Wood Ash To Improve Soil Fertility

Wood ash is rich in calcium, magnesium, potassium, and trace amounts of minerals. It helps in improving the fertility of the soil.

Wood ash may be a good addition to the soil to improve fertility. It is rich in nutrients that may boost the growth of tomato plants.

A study by scientists at the University of Kuopio in Finland showed that wood ash is a potent tomato fertilizer.

2. It boosted plant growth and increased fruit yield.

The wood ash is rich in calcium (20%), which is needed for the growth of tomato plants. It may also prevent the blossom end rot that happens due to calcium insufficiency.

It has potassium at a concentration of up to 5%, which may reduce the incidence of blotchy tomatoes and yellow shoulders.

The lack of magnesium causes yellowed, curled leaves. The wood ash provides magnesium to the plants that keep the tomato leaves strong and prevent the yellowing of leaves.

In addition, it has trace amounts of other nutrients, including iron, aluminum, manganese, zinc, and boron.

3. Wood Ash To Correct Soil Acidity

Wood ash is water-soluble. It may neutralize the soil acidity and help in making the nutrients available to the tomato plants.

Tomatoes prefer slightly acidic soil. However, if the pH is very low, it may be difficult for the tomatoes to survive.

Wood ash is water-soluble and contains lime that may help in neutralizing soil acidity. The carbonates found in the wood ash may react and neutralize the acid in the soil and increase its pH.

If there is an increase in the soil pH, it may increase the availability of nutrients in the soil and help in the growth of tomato plants.

Wood ash may be preferable over powdered limestone to increase the pH levels of the soil as it takes lesser time.

4. Wood Ash To Compost Heap

Wood ash may be added to the compost heap to balance the acidity of the compost. It may also provide a conducive environment for earthworms.

Another advantage is that you may add wood ash to the compost piles due to its high levels of potassium and alkalinity.

Sometimes, the compost may be acidic due to a lot of fruits. The addition of wood ash may balance the acidity of the compost. Also, it may help in providing better conditions for worms to speed the decomposition process.

5. Wood Ash May Help To Deter Snails

Wood ash may repel tiny snails and slugs from attacking the tomato plants. It has to be dry to work as a pest deterrent.

Tomato plants are troubled by snails and slugs that affect their growth. The snails and slugs don’t like to cross dry ashes. So, when they are spread around the tomato plants, they may deter the snails and slugs.

An experiment conducted by showed that wood ash may repel tiny snails and slugs efficiently. They turn around after coming in contact with the wall of ash.

However, the bigger slugs may secrete slime and cross over the wood ash. It doesn’t deter the bigger snails and

Also, if the ashes are not dry, they may turn into a paste and will not deter slugs.

Here is the experiment on wood ash repelling slugs and snails:

How to Add Wood Ash to Tomato Plants?

Gently sift the wood ash and spread it around tomato plants evenly up to one-half inch thickness. Pouring wood ash tea once a week may also work well for tomato plants.

One cord of firewood may yield 20 pounds of wood ash. A general rule of thumb is to add 20 pounds of wood ash to 1000 square feet of garden.

I prefer to sift wood ash and remove the large pieces. Then, I spread wood ash evenly up to one-half inch thickness. Do not leave the ashes in piles as they may leach into the soil and damage the roots. After use, always store the wood ash in an air-tight container.

You may check this video on how to use wood ash for tomato plants:

Some gardeners make tea with wood ash and use it for tomato plants for providing some nutrition.

You may put five pounds of ash in a permeable bag, close it, and allow it to sit in a 50-gallon garbage can filled with water for four days. Y

ou may then pour a cup around the tomato plants once a week when it starts flowering.

Considerations While Adding Wood Ash to Tomato Plants

Do not use wood ashes from trash or treated woods. Always cool the wood ash before adding it to the soil. Also, use protective gloves before handling wood ash.

Avoid using wood ashes from trash, cardboard, painted or treated woods. It may contain some chemicals that are toxic to tomato plants.

Do not use hot wood ash. Allow it to cool completely before adding to the soil. Also, wear gloves, eye protection, and a mask when handling wood ash.

Sprinkle the wood ash only in the base of the tomato plant. Avoid putting it on the leaves and stems of the plants.

As the wood ash is water-soluble, you should dry it completely before adding it to the soil. Else, it will wash away all the nutrients.

Other Uses Of Wood Ash

Apart from fertilizing the soil, wood ash may also be used to melt ice on the walkway, make soaps, hide stains, or neutralize the skunk odor on the pets.

There are many uses of wood ash apart from being a soil fertilizer. Some of the other uses of wood ash are discussed below.


How much wood ash is required for the tomato plant?

Tomatoes like wood ash due to their high potassium levels. You may spread a one-half-inch thickness of wood ash around the tomato plants. It is recommended to use a 5-gallon pail per 1000 square feet of garden.

Which plants prefer wood ash?

The plants including asparagus, conifers, and juniper prefer wood ashes as they may tolerate more alkalinity. But, do not add wood ashes for the plants like potatoes, parsley, blueberries, and rhododendrons as they prefer slightly acidic soil.


Wood ash can be a useful addition to your tomato plants and I hope this article has provided certain tips and considerations while using the wood ash.

If you have experience in using wood ash for tomato plants, comment below. Also, please feel to contact me for any queries.

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