How well a new lawn grown from grass seeds will grow depends a lot on the condition of the topsoil the seeds are sown in.

A big part of this is obviously how much actual topsoil there is for the grass seeds to grow in, though the quality of the topsoil is an equally important factor. Dry topsoil that has been stripped of its nutrients over time will not produce a healthy looking lawn, but even the driest and most nutrient-deficient soil can be improved.

Ideal Topsoil Depth for Grass Seeds

Dry topsoil that has been stripped of its nutrients over time will not produce a healthy looking lawn, but even the driest and most nutrient-deficient soil can be improved.

Growing a lawn from grass seeds requires topsoil that has enough nutrients and a good structural composition. The structure of the soil is what enables the roots to establish themselves and for enough water from rain and watering to be retained to further nourish the roots. To achieve this, you don’t necessarily need a ton of topsoil, but it can be a great help to lay a good layer of fresh top quality topsoil to a depth of about 10 to 15 cm.

A depth of 10 to 15cm is necessary for the roots of the grass seeds to properly establish themselves and produce a strong and healthy lawn. You can use a topsoil calculator to work out how much topsoil you have to buy in order to properly cover the entire area you are turning into a lawn.

There is some work to do before adding the layer of topsoil, however.

Soil Preparation

Before the topsoil is added, give the under soil a raking to help it blend into the topsoil when it gets added. This will also let you find stones and other debris that can be removed. Once the debris has been removed, including any weeds, the layer of topsoil can be added.

Soil Management

It is not absolutely necessary to add a compost into the topsoil as a quality topsoil will have plenty of nutrients for a new lawn. But if you want to give the nutrient content a boost or you know the old soil there is very nutrient deficient, then mixing some compost into the topsoil will only benefit your new lawn.

Planting Grass Seeds

After the topsoil has been laid, sow the seeds by hand or with a lawn spreader to get a more even distribution. Use a hand rake to work the seeds into the first centimetre or so of the topsoil. Once sown, water the seeds regularly for the first few weeks to keep the soil moist and try to avoid walking on the soil and fresh grass shoots until it has grown into a strong and healthy lawn.