Can your Turf handle the Summer HEAT ? ! ?

Hello, My name is Robbie Commens and I am the Sales Manager for Coastal Turf. Hot Lawn in Summer Months

Thank you for visisting our website. I hope that the information is useful!

During these hot summer months there are 3 main issues that MAY have a detrimental effect on the quality of your lawn. They are –

  1. Heat (during hot summer days)
  2. Lawn Grub (especially after rain)
  3. Mowing (as the grass is growing quicker on the warmer summer months)

For this weeks BLOG I would like to discuss the issue of HEAT. Heat causes small circles of turf to dry out and die, the circles will start off small but if nothing is done soon they will get bigger and bigger.This problem is very easy to manage and even easier to prevent, but first we need to learn how your lawn is very similar to the bitumen on the road and an old grizzly bear , sound weird?, heres the explanation why…….

The Bitumen on the Road is very similar to your lawn because they both absorb heat. We all know how hot the bitumen can get on a hot day, it might only be 35 degrees air temp but you try to cross that bitumen road in the middle of the day bare foot and you would swear it is more likely going to be above 45 degrees celcius. Your lawn is very similar to this. This happens because the bitumen (and grass) is last place for the heat to end up and is therefore absorbed. This means that the air temperature may be relatively cool at 30 degrees celcius but your the bitumen and your lawn will be much higher temperature than that !

Lesson to learn = *The ‘micro-environment’ of your lawn will be warmer than the air temperature.

Grizzly bears hibernate when the temperature does not suit them, your turf (all varieties) is exactly the same. If the temperature is too low, the turf will not grow / hibernates. If the temperature is too high the turf will not grow / hibernates. The growth of turf is similar to a bell shaped curve. The diagram below illustrates this (with Temperature being the horizontal X axis and amount of Growth being the vertical Y axis) –

bell shaped curve

As the temperature increase so too does the growth upto a certain stage (usually at around 32 degrees celcius). After that the growth of your lawn does not continue to increase with the increase in temperature. As the temperature increases the growth actually decreases. Therefore it is very important to keep your lawn at a constant temperautre of below 32 degress celcius as often as possible.

*Lesson to Learn = Your lawn stops growing once the temperature around the grass (micro-environment) exceeds 32 degrees celcius.

We now understand that the turf will be warmer than the air temperature and that once the temperature of the turf exceeds approx 32 degrees celcius the turf will begin to lose growth. But how can we use this info in regards to your lawn ? The best way to keep your lawn cool during hot summer days is a short irrigation / watering right in the middle of the day. THIS WILL NOT BURN THE TURF. The water, that is approx 15 degrees celcius, will cool the already warm turf (of approx 35 degrees celcius) back down to a comfortable 25 degrees celcius. Your Lawn will look greener, be softer and more resistant to pests if you do this, even just once a week !



  1. I loved the info !

    The info was easy to read, follow and made sense to a non green thumb like myself !


  2. Hiya I’m Victoria, The info you have provided will set me on my way to provide my new lawn with some tender loving care…. its like us, we like to cool down midday..
    Now I need to choose the right grass for the hot summer in south of perth in the coastal area, W.A. Could you give me some advise on which is the best with low maintenance

    kind regards…

  3. good advice, thanks. what about water evaporation? and bills? watering in the middle of the day? but the principle makes sense, …

  4. Good point Adam, you need to find a balance between spending excessive amounts of money through your water bill and securing your investment in your lawn. You will most likely find that a lawn that is not under heat stress will not require as much water to keep it lush. It is more about the timing of watering rather than the amount. It may take time for you to find that happy balance but we have used this principle with great success over the past 15 years not only on our installation lawns but also our farms. (Technical info – evaporation is a minimal loss compared to the evaportranspiration loss [evaportransperation = water loss through leaves during photosyntheseis}).

  5. Tall fiscue -I did my first mow and then the next day it was 38C and the lawn now has lots of brown patches .I kept watering it sometimes 3 times a day for the past 3 days and still there are no signs that it is improving .With tall fiscue how much watering does it need ,the lawn has been established now for 2 months.
    Iam worried that the brown patches are permanent damage since tall fiscue is not a creeper and wont rejunivate

  6. Hi Frank I’m really sorry but I don’t know that much about Tall Fiscue grass. If this is a seeded grass maybe overseeding may help to rejuvenate your lawn. Brown patches in turf grasses at this time of year is usually due to excess water, but I am not sure with seeded grasses, Sorry I can’t help, maybe conatact the peole you bought the seed from.

  7. Good reading will follow to the letter.have 205sq mtrs to lay.After just completing my retaining wall

  8. Thanks for the tips on the importance of heat on the lawn
    Also the tips on mowing
    My lawn is looking great

    Also Satah is really “on the ball”
    Always helpful and responsive to customer requests

  9. Hi
    I’m wondering if a spread of granule fertilizer is ok for the first week into March
    I have both Couch and Buffulo which I bought from Coastal
    It’s looking good right now but may need a little bit of boost during autumn

    Also just by way of feedback:
    Your advice on giving my lawan a little sprinkle in the day during our hot dry months we have experienced has done wonders for my lawn
    I notice my neighbours lawn has mostly died whereas mine looks good
    I done like to compare really, just letting you know that THAT TIP did the trick for my good-looking lawn
    Keep up the good work

    Steve Van Wyk

  10. Sare - Coastal Turf says

    Thanks so much Steve. I have flushed with pride and embarrassment. Thank you
    Granular fertilizer now is great, especially with the rain we are having. Chuck it out, like you are feeding chickens, across your lawn just before a shower of rain, or water the granules in. If you feel that there is a problem area in your lawn, add a little more fertilizer there. The rain is the best way to infuse your lawn with feed, so try and throw it out in these great showers we are having now.
    Chat Soon

  11. Hi Robbie Commens,
    I am from Adelaide in South Australia and was impressed with your reply in regards to the heat affecting my turf, and your reply about the Bitumen and Grizzly Bea comparison. My problem is an Instant lawn laid on Wed, Dec. 20th. Due to extreme temperatures as high as 43 degrees celcius have caused a problem. First I must mention I have a very efficient Sprinkler system., but on Wed. 16th Jan. the lawn lokked great except for a couple of patches. However 15 hours later on Thursday I went outside to turn on the sprinklers and to my shock half the lawn area was grey and dry. Where there is lawn it is long and lush but the rest looks dead. After all this do you think this new lawn will recover.? As a point opf interest the turf is called Conquest , which is a type of dwarf Kikuyu.

  12. Sare - Coastal Turf says

    Hi Paul. Thanks for getting in contact with us.
    I do not have a lot of experience with Conquest, although I have heard nice things about it. Ki tends to grow way too fast for us on the Gold Coast. Because the Ki does grow really fast, I would assume that it should recover well. But I would suggest going to your local Landscape yard and maybe asking them their best advice. Usually its the local gas who know your soils and are living through the same environmental conditions that will have the best advice.

  13. Pamela O'Byrne says

    Hot spell forecast late Jan 2018 so, although grass due a mow I held off till spell ended (almost a week). Noticed grass didn’t get too much longer. Was it correct not to mow and leave grass long to retain moisture? Is it best to leave catcher off when hot and let the grass clips mulch?
    Turned on head this mow as has been raining and growth phenomenal. Caught me on the hop. Lol. Is

  14. Sare - Coastal Turf says

    Hi Pamela,
    Yes that is right. I would take the catcher off, and leave the clippings on the lawn. This will break down and really help the long term health of your lawn. Rule of thumb is mulch twice collect once!
    And the rain is a welcome relief for us all!