How To Repair A Flood Damaged Lawn

We recently wrote a post on Repairing Your Lawn After A Natural Disaster. Today we will concentrate solely on lawns that have been submerged by water for more than 24 hours. Flooding can cause significant damage to lawns, however, this damage can take weeks or even months to show visible signs of this damage. The damage will depend on how long your lawn has been underwater, and whether or not the water was fast or slow moving.

Lawns will generally tolerate water well and many will spring back reasonably well after four days of total submersion. Others will start to wilt after just 24 hours – so observation is an important first start. So what do you need to be looking for after a flood?

  • Debris – floods often bring debris with them that are left behind as the water recedes.
  • Silt – the most common problem faced is the amount of silt that is left behind.
  • Erosion – the opposite problem to silt deposits is the removal of top soil from your lawn, often exposing roots

Once you have identified problem areas, it’s time to get to work, however, don’t rush in too soon. If the ground is still soggy underfoot, then foot traffic can cause more damage – in particular, soil compaction. Remove as much debris as possible as soon as possible – this will allow the soil to dry. If you have silt deposits, and you can still see blades of grass, then consider this silt a bonus layer of top soil. However, you will still need to bend your back. As that silt dries it will form a crust which will block out the sunlight from your lawn. You will need to use a steel rake to gently (don’t disturb the lawns roots) break up that silt as it dries – and you may need to do this daily for a week or more.

If you cannot see any grass, then the layer of silt is far too thick and will need removal. You can call in a professional, or you can use a rake to remove as much as possible – at least enough to allow the grass to see the sunlight. Floods can often leach a lot of your soils nutrients, they can also turn your soil acidic. Test your soil’s pH levels and adjust where necessary, then give your lawn a nitrogen balanced fertilizer. If you have access to compost, this is even better as it will also return organisms to your soil that may also have leached out.

Once your lawn has completely dried out, and this could take six to eight weeks, aerate your soil well. Floods often lead to soil compaction, especially if you have a clay-based soil, and this will hamper your lawn’s recovery. If areas have been stripped or thinned of grass, use a lawn repair tool to reseed those areas. You will also need to keep a careful watch for lawn diseases, remember, fungus loves warm wet conditions. Weeds may also be a problem having been washed in from areas outside of your homes boundaries.

When repairing a lawn after a flood, your main aim should be to minimize further damage, to get the sunlight into your lawn, and to ensure that nutrients and organisms are returned to the soil. Get that right and your lawn should bounce back well.



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