Harden Park Lawns has put together their top tips for summer watering:
How much is too much?
Overwatering can contribute to the development of fungi and disease and so should be avoided. The amount of water your lawn requires will depend on the variety of grass and environmental factors such as temperatures, humidity and wind.
As a general rule you should aim for 2.5 cms of water across the lawn each week. If your lawn takes on a blue-grey tinge or the outer blades of the lawn plants are curling or wilting, more watering is needed. Another indicator is whether or not your lawn ‘bounces back’ when walked on. If not, and 30-50% of your lawn is like this then you should water.
How often is too often?
Frequent and shallow watering encourages weed germination and shallow root growth allowing the lawn to become susceptible to drought and disease. Aim for deeper and less frequent watering to encourage a deeper and stronger root system. Just ensure that when you water that you penetrate right down to the root zone.
How deep is the root zone in your lawn? You can determine the depth of the root zone by digging a hole and seeing how far down the roots go.
How long is too long?
Now that you know how far down you need the water to penetrate you need to determine how much watering it will take to achieve this depth. Turn the hose or sprinkler on for 15mins and wait for 18-24 hours. To see how far the water has reached, dig a hole, use a probe or push a shovel into the lawn and use as a lever to separate the lawn and look for moisture. You can now use this approximation to during watering lengths. For example, If the soil is damp down to 10cms but your root zone reaches a depth of 20cms then you will need to water for 30mins.
As a general guide adding 2.5cms of water to your lawn will reach the following depths:
Sandy soils 30cms
Loamy soils 15-20 cms
Clay soils 10cms
Water early in the day
The best time to water is early in the morning, between 4 – 9am while the air is still cool. Avoid watering when it is hot, dry and windy as the water will evaporate and not reach the lawn plants.
Avoid using hot water
If your hose is left out in the sun it will heat the water inside through solar energy and make it hot enough to scald the lawn. Water while the water is still cold or if unavoidable, run the hose until the hot water is flushed out before applying to the lawn.
Watch the runoff
Watering running off your lawn is just a waste. If run off starts before you have given the lawn a deep watering stop for about 15-20 mins to allow the water to absorb and then continue. Runoff can be caused by excessive thatch so you may need to remove this if run off is a constant issue and is stopping water reaching the root system.
Sprinkler timers are a fantastic time saver however they will run regardless of the current weather conditions. Watering during rainfall is not only redundant and expensive but can lead to over-watering problems. Install a rain sensor – this will automatically turn off the sprinkler and timer when it rains. You can also utilise a rain gauge – this will show you how much your lawn has naturally received allowing you to just top up as needed.
If your local area is expecting rain and your soil is particularly dry, water to moisten and aid the absorption of the coming rain. And remember – don’t water just out of habit, watering when your lawn needs it.