For optimum growth, turf grass needs just four things (within the proper balance) to grow - sunlight, air, water and nutrients. Reduce any of these, or provide an excessive amount of any one, and naturally the grass may suffer or simply die. In the right proportions, the lawn will flourish.
Grass obtains three of these four essential factors (air, water and nutrients) from the soil, however many soils are less than ideal for growing grass. Some soils contain excessive amounts of clay and may even be very compacted... ideal for roads, bad for grass, because air and water aren't offered to the roots and the roots can't grow. Other soils may have an excessive amount of sand... beautiful on a beach, but difficult to grow grass because water and nutrients won't remain in the root zone long enough for the plant to use.
Another frequently observed problem regarding many soils is that its pH (the degree of acidity or alkalinity) is too high or too low for optimum grass growth. So getting the soil right is vital. Ideally you'd get the existing soil checked by a soil scientist, and he would let you know what it needs, but this is not always practical, yet it is feasible. Simply google soil laboratories and you'll find one. Other than getting advice from a soil scientist, there basic methods that can be used to prepare the soil.
Making sure you pick the correct method depends on budget and naturally the condition of the soil in the first place. First you need to kill any existing grass or weeds with Glyphosate. Sprying once will kill most things, however if you can, a follow up spray a few months later will certainly make sure everything is dead. Before Spraying make sure the weeds and undesirable grass is healthy, it even helps to water a number of times before spraying to make sure of it. Round Up works better if the weeds are growing well.
If you're lucky enough to have good soil, then simply hire a subcontractor who has a tractor rotary hoe, or hire a small one from a rental company to loosen the soil bed to, at the very least 100mm, and a maximum of 200mm. When the soil is too hard, water it well on the evening before. After rotary hoeing rake out any dead foliage if needed, and level the ground. When the soil is of a clay type, or a sandy type, or relatively poor in other ways, buy in some organic soil conditioner. Use at least 2 cubic metres per 100 square metres. Spread this over the soil. If it's a clay type use Gypsum as well. Use a rotary hoe to mix this well into the ground, and after that rake the ground smooth. Hiring a skid steer to do the work is another method. If you'd like to get a contractor to do the preparation, this makes life easier.
Be certain the operator rips the existing soil well first, loosening the base. A hard compacted sub soil is the last thing a lawn needs. Then order 7 cubic metres of good quality organic soil blend per 100 square metres or ground. Make sure it has a decent amount of organics in it. Spread this with the skid steer, making sure the finish is smooth. In some areas you may need to rake smooth with the back or front of a rake.
Turf is the safest and best way to install a lawn. Laying turf is absolutely easy. Seeding only works well in places like Tasmania where cool climate turf like Fescue is used. For Warm climate turf like Buffalo no seed is available, and for Couch and Kikuyu, the seed germinates very slowly, and is actually difficult to get a good result from.
Simply lay one roll all around the outside then fill in the area with the turf all going one way. Patch up any gaps, roll the lawn if you can, and water in well.
On hot days water the turf in sections as you lay it. Don't fertilise till a month after the turf is laid. University research proves that turf receives no benefit from fertilizer until a month after laying. Then make use of a good slow release type. For the first 2 weeks the lawn cannot dry out. On a hot day in summer that may mean watering 3 times per day, or on a milder day once per day. After 2 weeks, watering can often be reduced to every 2nd or 3rd day.
For more information on turf care visit www.ozbreed.com.au/gardening-articles.html