A Beginner’s Guide to Soil Amendments

There are different types of soil that have different characteristics. We have an article on all the soil types, but here’s a quick summary of their characteristics:

Clay soils:

  • Usually fertile
  • Hold a lot of water
  • Drain slowly
  • Easy to compact
  • Slow to warm up in the spring

Sandy soils:

  • Drain quickly
  • Warm up quickly in the spring
  • Don’t hold a lot of water or nutrients
  • Often have high acidity

Loamy soils:

  • A mixture of clay, sand, and silt
  • Usually fertile and well-drained

Chalky soils:

  • Lime-rich
  • Mostly composed of calcium carbonate
  • Very alkaline

Each of these soil types can present their own problems. Using soil amendments to alter the characteristics of your soil can allow you to grow a wider selection of plants and improve their health.

Compost and manure

Adding compost or manure to your soil is the go-to way to increase the nutrients. Both of these amendments also improve soil structure, loosening dense clay soils and bringing together loose sandy ones.

Coconut coir

Coir is the material from the outside of coconuts. It’s great at soaking up water and retaining nutrients, making it a great addition to sandy soils.


Woodchips are effective at aerating soils to give roots more space to grow and allow water and nutrients to move more freely. Composted woodchips are best because fresh wood can tie up the soil’s nitrogen so it doesn’t get to the plants.

Bone meal or blood meal

These soil amendments are the by-products of slaughterhouses. That may sound morbid, but this reduces waste and is excellent for plants. Bone meal is finely ground up bones; this is a good source of calcium and phosphate. These important nutrients help plants to produce bigger and better flowers and fruits. Blood meal is simply dried blood, and is high in another crucial plant nutrient: nitrogen.

Worm castings

Also known as vermicomposting, worm castings are excellent for some added nutrients and helping the soil to retain them. As well as nutrients, worm castings improve the aeration and water retention of the soil. This soil amendment is an all-rounder for healthier plants.


Lime is added to soils that are too acidic and makes them more alkaline. In gardens, limestone is used in the form of a fine powder and is easy to mix into the soil. Click here to learn about soil acidity and how to test the pH of your own soil.


Understanding your soil and using the appropriate soil amendments can do wonders for the health of your plant. To learn more about keeping your garden thriving, read our other plant care articles.

Updated on October 16, 2023

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