How to Prepare Ground for a New Lawn

Achieving a healthy lawn starts with proper ground preparation for lawn seeding. We will walk you through everything from preparing the ground for a new lawn, clearing existing vegetation, amending lawn soil, and levelling. Taking the time to prepare your soil properly will be worth it when you see the results!

Clearing the Existing Area

Now that you have planned out your new lawn, it is time to start preparing the ground. If the area currently has a lawn or other plants, it is best to clear everything first. Killing off existing vegetation will help minimise future weed and weed grass issues. Using glyphosate is recommended, as it breaks down upon contact with the soil, leaving no harmful residues. However, weed killers are only effective when temperatures are warm enough, typically between April and September. If you are preparing the ground before April, avoid using weed killer and opt for manual removal instead.

Removing Existing Turf

Whether or not you have sprayed weed killer, the next step is to strip off any existing turf. You can hire a spade, turf iron, or a petrol turf cutter. While this step might seem like extra work, it is essential to prevent the old turf from breaking down unevenly, which could lead to an uneven and bumpy lawn. If you have space, consider storing the removed turf to allow it to decompose into valuable compost or top dressing.

Clearing Stones, Roots, and Debris

Throughout the lawn preparation process, be prepared to remove stones, roots, and other debris. The level of thoroughness depends on the lawn quality you aim for. If striving for perfection, consider incorporating double-screened (1/4” sieved) sandy loam topsoil for the top layer.

Soil Testing and Amendment

If you have conducted a soil test, now is the time to plan and order the necessary amendments, which may include:

• Adding lime to highly acidic soils.
• Incorporating organic matter to improve sandy or heavy clay soils.
• Adding loam topsoil to sandy or light clay soils.
• Ensuring a soil depth of at least 4” with loam topsoil.
• Applying a pre-seeding fertiliser like Lawnsmith STARTER Lawn Feed.
   
  Caution: Avoid mixing sand or sandy loams into very heavy clay soils, which can cause the soil to set like concrete. If you need to amend heavy clay, remove it and replace it with an appropriate sandy loam to a depth of at least six inches, preferably a foot. If the soil remains heavy clay, consider installing drainage or consulting a professional.

Preparing the Seedbed

Double-digging or rotovating the soil to a depth of 6 to 8 inches (15 to 20 cm) is essential. While 10 cm is the minimum, it is worth putting in the effort to achieve a thorough preparation. Rotovate at least twice, and if the soil is not evenly tilled, repeat the process at right angles or break up large clods manually using a garden fork. Incorporate fertiliser at this stage.

Understanding Soil Types and Amendments

Heavy soils break up more quickly when dry, preventing smearing on rotavator blades, which could cause future drainage issues. Conversely, sandy soils might need slight moisture retention to maintain texture. The ideal condition is friable soil, neither clumpy clay nor loose sand.

Soil Amendment Process

When adding lime, avoid overdoing it, as excessive alkalinity can promote weeds and hinder fine grass growth. A soil test should guide the correct quantity. Even distribution is key to maintaining consistent pH levels throughout the lawn.

When incorporating soil amendments, blend them gradually rather than layering different soils on top of each other. Follow this process:

• For 6” (15cm) of new soil, divide it into three parts:
• Rotovate the first layer down to 20cm.
• Blend the second layer into the top 15cm.
• Incorporate the final layer into the top 10cm.
• For 4” (10cm) of new soil, divide into two layers and follow the abovementioned step.
• For 2” (5cm) of soil, mix it into the top 10cm only.
• Organic matter should be blended into the top 10 to 15cm.

Warning: Consolidate layers by treading. This process removes air pockets and prevents future settling, resulting in a smooth and even lawn surface.

Final Cleaning and Weed Prevention

Tilling the soil will bring weed seeds to the surface. To minimise future weed issues:

• If laying turf, weeds will not pose much of a problem.
• If seeding, increase the seed rate to outcompete weeds.
• If time allows, let the soil sit for a while to allow weeds to germinate, then spray with glyphosate a week before seeding.

For more information on Lawn Weed Control, read our help articles

Levelling and Compacting the Soil

Adding sand to heavy soil can improve drainage but must be thoroughly blended. River sand is ideal, whereas builders' or coastal sand should be avoided. Some professionals recommend applying a 1-inch layer of sand before seeding or laying turf, believing it enhances drainage. However, this practice is not advisable, as sand should be incorporated rather than layered. Instead, proper soil amendment, levelling, and smoothing are more effective.

At this stage, the lawn area is almost ready for seeding or turfing. Begin by raking the area to a smooth level using a landscaper’s or hay rake. The flat back of these rakes helps push and spread soil evenly.

Treading The Soil

This old-school technique ensures a firm, even surface. With most of your weight on your heels, shuffle, and tread across the area, covering every square inch to remove air pockets. This step prevents sinking later and creates a solid base for seeding or turfing. Repeat the process in different directions for an even finish.

After treading, rake the area again to eliminate bumps and fill depressions. Repeated treading, raking, and using boards or string levels may be necessary for ornamental lawns to achieve a perfectly flat surface.

If you have not applied a pre-seeding fertiliser, do so now or just before seeding or turfing.

Pre-Watering Before Seeding

Water the soil a few days before seeding to build moisture if the soil is dry. Post-seeding watering must be light to avoid displacing seeds. Watering before seeding also helps settle the soil, allowing final adjustments before sowing or laying turf.

Taking the time to prepare your lawn correctly will ensure a healthier, more resilient, and visually stunning result for years.

Check out our lawn care advice section for more information on creating a new lawn.

Other Relevant Blogs

• Planning the New Lawn
• How to Sow Grass Seed
• How to Lay Turf
• How to Water Grass Seed
• All about Grass Seed Germination