Topsoil is one of the most important components in ensuring a healthy lawn. It is the foundation of any lawn turf job and hence it is essential to know the composition, quality & source. Topsoil is what provides the lawn with nutrients, controls the amount of moisture your lawn receives, and ensures it receives the necessary oxygen.
When planning to lay a new lawn, it is important to check that your existing soil is up to the mark. Soil preparation is the most time-consuming part of laying the lawn, but it will ensure your lawn gets off to the best possible start.
You should have a minimum of 150mm of soil under your lawn. If you are planning a new lawn to assess the quality of your existing soil please refer to the how to assess the quality of your soil element of the How To Section of the website.
WHAT’S IN TOPSOIL
Topsoil is the layer of soil that the grass takes its nutrients from and is rich in organic matter. The main contents of topsoil are nitrogen, phosphorous, potassium, and magnesium. Each element plays a significant role in the fertility of the soil.
- Nitrogen is used for growth
- Potassium and magnesium help the grass to photosynthesize which creates the lush green lawn
- Phosphorus is what helps the grass create a strong root network and promotes tillering which provides the thick swarth
Another property of topsoil that is important is that it is made up of a balance of sand, silt, and clay. This is known as a loam soil. Loam soils are typically around 15% clay, 35% silt, and 50% sand. If your soil contains too much sand, it will not be able to hold the nutrients in the topsoil and it will be washed down to the subsoil similarly if your soil contains too much clay it will waterlog. At The Lawnturf Farm, our soil has been tested to confirm the optimal balance of each component. Loam soil holds moisture but also drains well when you water the lawn. It is able to retain nutrients and allow airflow making it the most ideal soil for plants.
HOW MUCH DO YOU NEED
Topsoil is sold by the tonne. 1 tonne of topsoil will cover 30m2 of the lawn area with 1 inch (or 25 cm) in depth. For example, if you want to add two inches to 60m2 you will need four inches of topsoil. If you are unsure of how much topsoil you need please do not hesitate to contact us.