Why deep and infrequent
Roots grow towards water. If the only water available is in the top two centimetres every evening, that is where the entire root system stays — and a lawn with roots two centimetres deep has no reserve at all when a 38-degree day arrives.
Soak it properly once a week and the water moves down through the profile. The roots follow it, and the lawn can then draw on moisture that the sun cannot reach.
How much is a soak
Aim to wet the soil to about 10 to 15cm down. The simplest check is a long screwdriver: push it into the lawn after watering, and where it stops pushing in easily is where the water stopped.
To measure what your sprinkler is actually putting out, sit a few empty tuna tins around the area and time how long it takes to collect about 20mm. That tells you your run time, and you will only ever need to do it once.
Water in the early morning
Just after sunrise is the right time. Less is lost to evaporation and wind than in the middle of the day, and the leaf has the whole day to dry out.
Evening watering is the one to avoid on the Central Coast. Grass that stays wet through a warm, humid, still night is exactly the condition fungal disease is waiting for.
How to tell it actually needs water
Those signs beat any schedule. A lawn under shade cloth of trees in June needs a fraction of what the same lawn needs in open sun in January.
- Footprints stay visible on the lawn instead of springing back.
- The leaf blades fold in on themselves lengthways.
- The colour shifts from green towards a dull grey-blue before it goes brown.
New turf is completely different
Freshly laid turf has no root contact with the soil below, so it dries out fast and cannot self-rescue. It needs watering every day, and in hot weather twice a day, for the first couple of weeks.
Once it has knitted down and you cannot lift a corner, start stretching the interval out and cutting back to a deep weekly soak. Going straight to weekly watering is the most common way new turf gets lost.
Check the restrictions
Water restrictions on the Central Coast change with storage levels, and they set what days and hours you can use a sprinkler. Check with Central Coast Council before you put a timer on anything.