Basic care for your lawn

In the early stages of your new lawn, just walk over it once a week to remove any weeds that may appear out of your subsoil. (Weed seed can still germinate in soil any time up to twenty years later.) Once your lawn starts to thicken up, if you keep it healthy with fertiliser and water, you will eliminate the conditions favourable for weeds to exist. Don’t treat your lawn under one general rule. For example, you may have a shady damp area so back off with the water and maybe mow it higher or if a tree is shading an area, try to trim your branches to a height of about one and a half metres from the ground to allow sunlight to access your lawn. Remember a lot of the time it’s not just the shade from a tree but also the tree is taking the nutrients out of the ground in which case you would require extra fertiliser in that area. Areas that are shaded still require 2 to 3 hours sun per day otherwise turf will die off after a couple of years due to the lack of sun. This type of area would be best turfed from late winter onwards to give it a better start in life.

Army worms

These pests eat the leaves off your lawn and usually start with the best lawns first. The first signs you will see of these is a small grey moth flying at night time under lights. They then lay eggs in your turf that hatch into grubs. If you suspect the grubs are present, pour some warm soapy water on a small patch of your turf and they will come to the surface. Or put a dark blanket over the lawn for ten minutes to make them think it is night time and they will also come to the surface. A chemical called Bathroid can be used to treat them but it is best to contact your local nursery for further advice.

Weeds

Broadleaf weeds can be sprayed out of your lawn, such as bindi, thistles, etc. This may be sprayed with Bromoxane or ask your local garden centre. Use these chemicals strictly by instructions. Once again, if you keep your lawn in top condition you will not get weeds.

In the event that you get clover in your lawn, weed it out while it is still small as if you let it get big it becomes very difficult to control.

Top dressing

Is only necessary to correct any uneven marks in the lawn after being mowed a couple of times. However, if you do top-dress lightly straight after you lay your turf, this will prevent it drying out so quick and make it easier to maintain. This should not be done during non-growing times (winter) and should be done so the turf is visible, as too much topsoil will smother the grass. For a good even result, use the back of a rake or broom to brush the topsoil into the holes. The maximum topdressing to be used at any one time should be about 10mm.

Watering

When you first install your lawn, saturate it to give it a good start then keep it moist for the next few weeks. Check for moisture by lifting the turf to look underneath it. If the lawn starts to dry out too much, it will start to go a grey colour. Once your lawn is established, it is recommended you give it one big drink rather than several little ones as this will penetrate deeper and allow the roots to go further down. When water restrictions apply check your rights at www.sydneywater.com.au to ensure you are doing the right thing.

Mowing

Your first light mowing should take place after the turf has taken root. You will know this by trying to lift the turf like pulling someone’s hair. If the turf stays put, you know you are right to mow. If you allow the turf to get too long don’t mow it anymore than 1/3 of its height at a time. Mow it 2 or 3 times over a week or 10 days gradually lowering the mower each time. If you don’t obey this rule, you could find you will get a lot of die back in your lawn especially in humid weather. Mowing heights can vary from 15mm to 50mm. However correct height can depend on personal preferences. Mow at the higher level in shady areas and also prior to winter. Generally a longer leaf will encourage the root system. In the early spring when the turf has started to grow again you can mow the turf short again a couple of times to get rid of the thatch (Remember the “1/3 of it’s height” rule). I cannot emphasise enough how important it is to keep your mower blades sharp and in top condition, as blunt blades will also cause dieback in your lawn, once again especially in humid weather.

PH LEVELS

Acid or Alkaline?

Soil pH is a measure of its acidity and alkalinity. On a scale of 1-14, 1 is the most acid and 14 is the most alkaline; 7 is neutral, neither acid nor alkaline. The best pH for grass is between 6 ( a little acid) and 7.2 (very slightly alkaline). Some soils are naturally alkaline but in most parts of Australia soils are more likely to be a bit acid. What we add to soil, notably fertilisers, can change its pH. Lime raises the pH of soil, making it more alkaline, but other fertilisers tend to be acidic. Sulphate of ammonia, a fast acting fertiliser for lawns is highly acidic and its habitual use will lower soil pH overtime. Other lawn foods are also acidic but not as strongly so as sulphate of ammonia.

Why pH matters

When soil pH drops below or rises above its ideal for lawns, certain nutrients in the soil become harder for the grass plants to extract. The lawn may start to go yellow with thinner growth and no matter how much fertiliser you apply it has no effect on the grass (and it could be making the pH problem worse).

How to Correct

If the soil is too acid (that is, below a pH of 6), dust the lawn with agricultural lime and water it in. If the soil is too alkaline (above pH7.2) use powdered sulphur or sulphate of ammonia dissolved in water. Don’t be too enthusiastic in your application. It is much better to raise or lower pH in small steps about a month apart rather than in one big concentrated hit. After application, water the lawn well and continue to do so weekly. Test the soil again a month later when the material has had time to work.

How to Test

To test the pH of the soil, buy a pH test kit at the nursery. They cost around $20-$40. To use the, just mix up a small soil sample with a liquid on a mixing plate, then dust it with powder (both are supplied in the kit). After a minute or two you compare the colour of the sample with the colour chart (also supplied). Full directions are in the kit. These kits are very easy to use, readily available and they could diagnose your lawn problem in just a few minutes.