Helping your lawn recover after flooding

The recent rains experienced in many areas of the country have caused an extensive amount of damage to homes, businesses and to our outside living spaces.

The most important thing is the health of your families and supporting our communities, so stay safe and we wish everyone the best in the weeks ahead.

The biggest challenges faced during these times for lawns is the combination of water logging for extended periods, but in addition to this, once the water levels drop the soil and sediment left behind can smother lawns and are a significant barrier for recovery.

What can you do?

Firstly, make sure your lawn is safe. If rain is still coming down excessively and flowing water is still present, please wait. Make sure all hazards have been identified and addressed so you do not put yourself in harms way.

Facilitate water absorption and the draining away of excess water as best you can, as soon as possible and when safe to do so.

The best thing is for the rain to stop and for the lawn’s moisture level to return to a manageable level. Sunshine is the biggest influence on this, but you can aerate with a garden fork after a few days, divert water away from the lawn where possible and remove all debris that you can that could restrict direct sunlight to the grass.

Aeration is of particular importance for alleviating the moisture and allowing oxygen down into the waterlogged roots of the lawn. You can read more information about aeration here.

We have seen in some lawns a lot of mud and river silt left behind smothering grass once waters have receded. Remove what you can by hand and make sure you are wearing gloves. Although more water sounds counterintuitive, initially it can be a good thing to try and use a hose with high pressure to blast as much of this into or off the lawn, so the grass blades are unobstructed.

Another tip for removing any mud/silt/debris easily is using an old rotary mower with a catcher if you have one, as these are great at picking up debris on a lawn.

If moss or algae are present this too will need addressing, you can find more information on treating moss in our blog here.

Initially we would advise not to use any fertilisers, topdressing, or other amendments until you are certain the worst of the rain has passed, the lawn is drying out and you are seeing signs of growth. You don’t want to run the risk of wasting money on product that’s going to get washed away or could do more harm than good if likely to stress an already unhealthy lawn. You can however, hand weed, or spot treat any weeds that have popped up, as it is likely weeds will have infiltrated and it’s going to be important to address this so that they don’t get out of control.

When there is excessive moisture combined with humidity, it is common for turf disease to develop. Once the conditions that are causing the disease to develop are gone, your lawn in many cases should recover on its own. Aeration as mentioned above will significantly help with this, but if disease symptoms persist, you may need to look at doing a fungicide application to help improve turf grass health moving forwards.

If you notice the lawn is showing signs of being hydrophobic where the water is being repelled by the soil and pooling rather than absorbing quickly, then a wetting agent application will help with this. A product like Wettasoil or Lawn Soaker is ideal.

As soon as it is dry enough to do so without making much of a mess, mow the lawn at your normal mowing height. If the lawn has been left for an extended period and has some length to it, a reset may be required to bring the stem of the grass down to a lower height. This will involve taking the mower down a notch or two lower than normal (lightly scalping) before bringing the mower back up to the normal height. Getting back into regular mowing as soon as possible will be a big part in promoting healthy lateral growth for recovery. Dethatching or scarifying to remove any loose thatch or debris within the profile that has developed before or during the flooding is also going to aid significantly in recovery.

Once the lawn is showing significant signs of recovery, you can fertilise the lawn and target any weeds that have washed in more aggressively. It can be a really good time to also apply a pre-emergent herbicide like Oxa-Pro (20kg) that can help to prevent the emergence of some of the weed seeds that have likely been washed in.

We hope this information is helpful. There are no easy solutions unfortunately, but if you address the things mentioned above it will go a long way to speeding up the recovery process.

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