While your lawn may not be high on your list of priorities after the recent floods, a few timely actions will improve the chances of your lawn’s recovery. There are issues that are extremely apparent – soil loss, debris, sediment, broken branches – but others will take a little while to be obvious. Even short-term flooding of your lawn has the potential to damage the soil and the root systems. While the soil is flooded the oxygen is eliminated – and, of course, oxygen is vital for root respiration and soil microbes.
Depending on the variety of lawn you have, as little as 24 hours of complete immersion can cause damage to the roots and the plants above. Most plants can survive being submerged for about a week but the damage to the roots below can make the plants susceptible to disease and pests while also making them less tolerant to high temperatures and water deficiencies. Any heavy accumulation of soil or sediment can also be as damaging as standing water for depriving the roots of oxygen.
Lawns can usually survive up to four days of water submersion but care must be taken even once the water drains away. Avoid traffic on the lawn on waterlogged soils as it will be prone to soil compaction. The very best thing to do after a flood is to let the water drain away naturally before attempting to undertake any recovery tasks. The first step of flooded lawn recovery is to remove any debris – wear appropriate shoes, long-sleeves and gloves to avoid cuts and scratches. Next, deal with any accumulated silt, soil sediment or organic debris. Less than 20mm of sediment can be spread around with a rake to provide the lawn with a useful layer of top dressing. Ensure it stays loose and does not crust over preventing air movement. Remember there is still lawn below so don’t drag the rake across with too heavy a hand.
Lawns with more than 20mm of sediment have a harder road to recovery ahead of them, but if the excess sediment is removed quickly and the surface remains well-aerated then it has a chance. If you don’t see any signs of regeneration within weeks then it might be time to consider re-establishing your lawn. Part 2 of lawns after floods can be found here.
For more information or help if you need to replace your lawn after the floods just contact our team at Daleys Turf.