Is Wood Ash Good for Grass? (When and How to Use)

Wood ash forms when the wood is burnt in fireplaces, bonfires, or power plants. It is largely composed of calcium compounds and other elements usually present in the wood. While most people don’t find it useful, wood ash can be used for soil enrichment and amendments. This brings us to the question; is wood ash good for grass?

Yes, wood ash is a great source of potassium, calcium carbonate, and other minerals which are helpful for the proper growth of the grass. Wood ash can also be used as a natural liming agent for neutralizing high soil acidity.

Is Wood Ash Good for Grass?

Yes, wood ash is good for grass BUT before you use it on your lawn, there are important things you need to know.

Wood ash is a great source of potassium, calcium carbonate, and other minerals which are important for plant health including lawn grasses. Nutritional content may vary based on the type of wood used. Hardwood trees such as oak produce quality ash compared to softwoods like pine.

Calcium carbonate is a liming agent, which makes wood ash great for raising soil pH. When soil pH drops below 6.0, it limits the ability of plants to absorb essential nutrients like nitrogen, phosphorus, and iron.

Most lawns and garden plants thrive in soils with a pH range of 6.0 to 7.0. Few plants will need lower or higher soil pH. if you suspect acidity in your soil, simply apply a wood ash solution.

Before you use wood ash in your garden, begin by testing your soil pH. Add wood ash to your lawn only when the pH is falling below 6.0. Do not use it when your soil is already alkaline with a pH value greater than 7.0.

Further, ash should not be used around acid-loving plants like azaleas, blueberries, rhododendrons, and camellias among others.

How to use Wood Ash on Grass

Wood ash is water soluble thus expect it to change soil pH rapidly as compared to limestone. When using it on your lawn, apply it with caution and precision as for other fertilizers. Wear gloves, protective clothing, protective eyewear, and a dust mask before you begin.

Mow your lawn short then moisten it before you spread the ash. On a calm day without winds, spread ash evenly on the grass. 10 to 15 pounds will be enough per 1,000 square feet. Rake slightly to distribute the ash and thoroughly water your lawn after finishing.

It will only take a few days for wood ash to raise your soil pH. Give your lawn at least one month before you apply any nitrogen fertilizer. You can only reapply ash after a period of about five years or when soil tests confirm the need to do so.

Too much wood ash on the lawn has a great potential of damaging your grass.

Other uses of Wood Ash in a Garden

Apart from raising the soil pH, wood ash can also have many other uses in the garden which include the following:

1. A compost ingredient

Wood ash can also be added to a compost pile to lower the acidity of decomposing materials. It can be used in thin layers between decomposing nitrogen-rich materials like grass clippings, manure, and vegetable scraps.

Wood ash in compost can also be a valuable source of potassium, calcium carbonate, and other trace elements. If you don’t like the smell of your compost, the ash will also neutralize the odors.

However, moderate amounts of wood ash should be used in compost to avoid making your manure highly alkaline.

2. Pest Control

Wood ash is also helpful for controlling pests such as aphids, cutworms, snails, and slugs. Simply apply it directly in a powdery form on the affected plants or mix it with water to form a liquid solution. Make your application on a calm day without rain or winds.


The application of wood ash on your lawn can help in lowering soil pH. Do not just use any type of ash, consider using one from burning hardwood logs. Before applying wood ash to your grass, be sure to conduct a soil pH test.

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