Central Landscapes Pebbles and Decorative Stones Guide

Topsoil is the top layer of garden soil. This guide will allow you to understand the key components of topsoil, what topsoil is used for, and how to maximise the potential of topsoil.

What is topsoil?

Topsoil is the top layer of soil in any garden or field. Usually, it refers to a depth of between 5 to 20 centimetres down. 

The topsoil layer is where nutrients are delivered to plants, where water is absorbed, where sunlight helps to aid the growing process, and where earthworms and microorganisms interact with the plant in various ways. This makes topsoil the most productive and important section of garden soil.

What does topsoil have in it?

Topsoil is a mixture of sand, silt, clay and broken-down organic matter, called humus. Humus is rich, highly decomposed organic matter mostly made from dead plants, crunched-up leaves, dead insects and twigs. Topsoil is not weed-free as a general rule, as it has not been treated to remove weed seeds.

How is topsoil different from other types of soil?

Topsoil is different from other garden mixes, composts, and potting mixes because it is the foundation that other garden mixes and composts are mixed into to amplify your soil quality. Topsoil is the upper, outermost layer of your garden, it is where the majority of microorganisms, biological soil activity, and plant roots fall. 

Products like compost and garden mix are frequently added underneath or within topsoil to increase its functionality, including improving the texture of topsoil.

Topsoil vs Compost

The difference between topsoil and compost is that compost isn’t actually ‘soil’. It is a blend of natural materials broken down into organic matter rich in nutrients that serve as a natural fertiliser.

Compost can be added to topsoil to improve its structure, reduce compaction, and improve water retention and drainage.

Topsoil vs Garden Mix

The difference between topsoil and garden mix is that topsoil is a versatile landscaping material used for various purposes, while garden mix  is a soil-less, weed-free blend, ready for planting into, that has been enriched to enhance its suitability for plant growth.

Topsoil vs Nutra Soil

Nutra soil is a 50/50 blend of topsoil and garden mix, offering the best of both worlds: the heavier texture of topsoil and the fertilisers and compost components of the garden mix. Due to topsoil being present this mix cannot be sold as ‘weed-free.’

Topsoil vs Potting Mix

The difference between topsoil and potting mix is that potting mix is commercially manufactured to meet the specific requirements of plants that are grown in pots or containers.

Topsoil is mostly used for landscaping or to be added to other types of soil in gardens or raised beds. Unlike potting mix, topsoil will often contain decaying organic matter, sand, clay and other materials.

What is topsoil used for?

Topsoil is widely used in gardening and landscaping. Here are some of its common uses.

As a base for a new lawn/topping up an existing one

Topsoil is an ideal base to fill or level an area that is being sown for a lawn. It should also be used for filling deep (+5cm) holes in existing lawns. Because it is not weed free, it is recommended to cover topsoil with a lawn mix such as Premium lawn soil before seeding the lawn. The top layer will encourage the grass to germinate, offer nutrients to nourish young grass and be weed-free. The topsoil beneath offers the perfect structure to encourage the grass roots to grow down and aids good lawn establishment.

Related:
Sowing lawns: go early, go hard.
How to sow a lawn

Another H2

These mixes can be applied during spring or autumn to encourage lawn growth and top up gaps. Dressing with these mixes is a great way to maintain the quality of your lawn.