Preparing soil for lawn installation

8 Minute(s) read

Your guide to proper soil preparation for new instant turf

Knowing how to lay new turf is an important skill for all groundspeople and gardeners to know. We find laying is a great skill for people at any level of experience to learn or perfect. Preparing and laying new turf is just challenging enough to work up a sweat, but not so difficult that you can’t get the job done yourself (with a little patience, of course.)

In this guide, we’ll teach you everything you need to know about soil preparation for a new lawn. Then, we’ll give you a rundown on DIY turf installation so you can lay a perfect new lawn.

Let’s get started.

Measure your lawn area and order your new turf

First, get out the tape measure. Measuring lawns is the easiest part of the process, but we’ve seen corner-cutters muck it up by estimating the surface area of their existing lawn with footsteps.

The formula for calculating your lawn’s surface area is width x length. If you need a hand, feel free to use our turf calculator. 

Calculating the surface area of a rectangular block of existing soil is easy, but things can get complicated if you have an oddly shaped lawn with curved edges, paths and odd angles. Make the job easier by breaking the lawn into smaller, simpler shapes like rectangles, triangles, circles and semi-circles. Our turf calculator can easily manage those for you.

Pro tip: ask us to schedule your turf delivery after you expect to have finished all of your soil preparation work. That way, you can install your new turf immediately.

Assess the quality of your existing soil

There are several soil factors you’ll need to address to give your instant turf the best chance to thrive.

Soil type: the best soil for instant turf is loam soil, which is a combination of sand, silt and clay. If you’ve got dense clay, rock, loose sand or any other poor growing medium, you’ll need to remove it and replace it with good-quality sandy loam soil.

Compaction: if your existing lawn is already bedded with loam soil, you may find that regular use has compacted the soil into a dense crust. You can loosen your soil properly using a rotary hoe or lawn aerator and then adding gypsum to the soil.

Drainage: standing surface water can kill your grass and attract disease-carrying pests. Poor soil drainage can kill grass, too. Well-aerated loam soil can help, but it’s best to lay your soil on a gentle decline away from your home. If your soil’s quite dry, you’ll need to apply a wetting agent to help it hold onto water for your turf’s roots.

pH: you can test your soil’s pH level using a soil meter, which you can buy from any reputable gardening supply store. Your soil’s pH level should sit anywhere between 6.5 and 7.5. You can make your soil’s pH level more acidic using any sulphur-based fertiliser. You can make your soil’s pH more alkaline by adding lime or dolomite lime.

Clear your soil of weeds and debris

It’s best to begin by clearing out debris such as rocks, stones, sticks, and weeds. Do this by running a rake through the soil to pull up any hard debris. We recommend you go over your soil a few times in different directions to ensure you’ve thoroughly cleared it.

Once that’s done, you’ll need to ensure you’ve killed off all weeds. We have several effective weed killers that’ll do the trick. Weed killers like Roundup or glyphosate can be used up to seven days before you start cultivating your new lawn.

Ready your topsoil

To make sure your finished lawn is level with any walkways and paths, you’ll need to make sure the soil is at the correct depth to accommodate the thickness of your chosen turf. For Sir Walter turf, the soil will need to stop at a depth of 25mm. For TifTuf, Sir Grange and Eureka turf, the soil will need to stop at a depth of 20mm.

Prepare a base of 100mm of well-worked soil. If your existing soil is suitable, this may be as simple as rotary hoeing the soil. If your existing soil is poor quality, you will need to apply a blended soil mix evenly across the area. Your local garden supplier can advise you on the correct turf blend soil to use in your area.

Lay your new turf

Ideally, your turf delivery should coincide perfectly with the end of our soil preparation process. Time to get your hands dirty. 

Pro tip: As you lay your turf, keep in mind that you must avoid standing or kneeling on your fresh turf and avoid stretching the rolls so that you don’t break up the soil and roots.

Apply your complimentary starter fertiliser pellets to the prepared area, aiming for an even coating. We provide free starter fertiliser with every order as well as an optional upgrade to our super starter pack.

Begin laying your turf along a straight edge, such as a driveway or path, starting at the corner furthest from the stack of turf rolls. You’ll lay the next roll behind it to create a line of grass. The heels of each roll should butt against each other, but should not overlap to avoid die-off.

It’s best to avoid having the seams in each adjacent line of turf line up, to improve moisture retention. To do that, stagger the turf rolls in each adjacent line to create a brick-like pattern. 

If your turf comes up against objects like trees, planters or ornaments, lay the rolls of turf up against them and then trim the strip of turf with a sharp knife or hedge shears to fit. You should end up with a perfect grass border.

Where steep slopes exist, lay your turf in lines across the slope and not down the slope. This will ensure that wet turf doesn’t slough down the slope before the roots have taken.

Once your turf is laid, you can use a lawn roller to smooth out any air pockets. Work backwards from the farthest corner to end with a perfectly smooth surface. Do be gentle so as not to break up the soil.

Pro tip: Thoroughly water your freshly-laid turf as soon as possible, ideally within 30 minutes. 

You’ll need to keep your new turf wet for at least four weeks once it’s laid to get the roots to take. After that, water once every two weeks to encourage the roots to dig down deep.

Common questions and helpful answers

When in the year is the best time to lay turf?

You can lay turf during any season. However, if you have enough shade, it’s best to install your turf during the spring and summer months.

Is it better to lay turf or seed?

It’s far quicker and much more affordable to lay instant turf than it is to seed a lawn. Grass seeds require a great deal more water than instant lawn, and can drive up your bills significantly. Also, since turf is already thickly set, it’s far more resistant to weed infestation than seeds are.

How long can I keep my turf rolls before laying them?

Once your turf rolls are delivered, they’ll begin to yellow and wilt that same day. You should aim to lay your new turf the day they arrive.

When will my grass be ready for me to walk on?

Your turf needs time to establish. This can take between 2 weeks to 10 weeks depending on the time of the year.

You can check how strong its hold is by gently trying to lift the turf: if it has good resistance, you can start to walk on it. 

But be gentle. Your lawn won’t be ready for a game of backyard cricket for a few weeks. At first, try to keep activity to a minimum and only go out for watering and mowing.

When is it safe for me to mow my newly laid lawn?

You can mow your new lawn once the roots have taken hold. Gently grasp a tuft of grass and try to lift the turf — if it resists, then your grass is ready to mow.

Here is our general guide for mowing times during the active growing season of spring, summer & autumn:

• TifTuf: mow after 5 to 7 days
• Sir Walter DNA Certified: mow after 2 weeks
• Eureka Premium Kikuyu VG: mow after 7 to 14 days