
The Australian Summer is a highly stressful time for all lawns, and it's the things we do both before and during the Summer which will determine the overall health and appearance of our lawns.
Generally speaking, we need to prepare the lawn to withstand the heat of Summer by ensuring it is in the best health and condition prior to the onset of the heat, as well as to avoid any sudden shock to the lawn
Our aim here is to create a root system which is much deeper than normal, with a deep root system, the roots of the turf are less likely to dry out and die on hot Summer days, or at times of drought or low water usage.
The way this is done is to water the lawn less often, and more deeply. Aim to reduce watering frequencies to half of normal or even less, and when the lawn finally begins to start looking slightly wilted, it's time to give the lawn a very large drink of water.
In this way, the lawns roots will continue to travel deeper into the soil profile, where they are safe from Summer heat, and where there is an abundant supply of water which resides below the soil evaporation level.
Watering a heavily thatched lawn will result in a lot of the watered being applied being left to sit in the thatch layer of the lawn, with the end result that less water reaches the soil to maintain the health of the lawn, and instead… simply evaporates away in the heat of the day. This problem is further compounded when the lawn is being watered at night, which provides a perfect breeding environment for lawn diseases.
Lawns, and in particular Couch should be de-thatched (vertimowed) every year or two, and done in the Spring. Varieties such as Buffalo or Kikuyu can be mowed much lower at the beginning of Spring instead.
Wetting Agents are a wonderful invention for every lawn and garden owner around the world. As many soil types begin to dry out in the heat of Summer, they also tend to become more water repellent too. Meaning water will more likely run off the soil, and the soil will not hold onto the water for a very long period of time.
Wetting Agents soak into the soil and coat the particles with a water attracting agent which breaks down any greasy coating on the surface of the soil particle. This allows soils to hold onto water for longer periods of time, as well as allowing dry soils to soak up much more water than would otherwise be the case.

The first change to lawn mowing should be with mowing heights, if the lawn is in excellent health and water is not an issue, then lawn mowing heights can safely be lowered, as the time of year is peak growing season and the lawn can easily cope and repair with a shorter leaf.
However, and this is a BIG however…. if the lawn is subject to heavy water restrictions and may experience drought-like conditions, then the lawn mowing height should be INCREASED. This will allow the lawn leaf and thatch layer to insulate the soil against heavy water loss from evaporation, and the end result will be massive as the Summer progresses.
Lastly, mow the lawn regularly during the Summer. Healthy, well watered lawns will benefit from less weeds and more green leaf with less invasion of the grass into surrounding garden beds. Regular mowing will also ensure the lawn is not scalped by removing too much green leaf in a single mowing, as this can easily kill sections of lawn which are under the stress of Summer heat.
If you've found yourself with a string of very hot days and the lawn looks to be under extreme stress and at risk of possibly dying, then the very best thing to do is to give the lawn a very deep watering the next morning. Also ensure the lawn receives and application of Wetting Agents at the next available opportunity.
The hottest days of Summer are the most stressful of all for any lawn variety. On these days it's important not to put the lawn under any further stress whatsoever, otherwise the results can become extremely damaging to the lawn for a very long time to come, even possibly causing the death of the lawn.
Weed Sprays
All chemical treatments should be completely avoided unless they are being applied by a licensed and trained professional. These include weed sprays, insecticides and fungicides.
Fertilising
As a rule of thumb, all fertilising should also be avoided on the hottest days, as the results can be devastating to the lawn if the fertiliser is not watered into the grass thoroughly and completely, and done immediately after application. If you really must fertilise a lawn on a hot day, do it early in the morning and ensure the fertiliser is completely watered away from the grass leaf and into the soil. For safety's sake, best to leave fertilising on all of the hottest days.
Lawn Repair
All forms of lawn repair should be avoided in the heat of Summer. This includes things like top dressing and mowing overgrown lawns.
Highly respected Australian turf and plant breeder Todd Layt shares expert lawn care advice with homeowners on The Lawn Guide.