Were you taking a stroll on your lawn and suddenly feeling the turf was squishier than usual, or noticed that your garden plants are all of a sudden all wilted and tilted? Well, chances are, your lawn is sinking.
Now what does that even mean? Don’t get scared by the word “sinking” because it is nothing major and fixable. By lawn sinking, we mean that the lawn’s soil is subsiding, which can happen for many reasons.
Some of the main reasons can be soil erosion and underground cavities, but they can be fixed. We will be discussing everything you need to know to identify if your lawn is actually sinking, why it is happening, and how to fix it. So without skipping, keep reading ahead.
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How do You Know if Your Lawn Sinks?
So before you jump to the conclusion that your lawn is sinking, let’s confirm it is. When can you say that the lawn is sinking? Here are some signs you should look for.
1. Undulating Surface
Look closely and see if your lawn has unevenness across its length and breadth. If your lawn seems noticeably more uneven, sunken or has random depressions, there’s a chance that your lawn is sinking.
2. Cracks and Sinkholes
If you notice that the soil near fences, garden structures, and walls is cracking or widening, or you see sinkholes appearing out of nowhere, it can be a clear sign of the topsoil sinking. Especially check for the appearance of holes, as they signify that the soil or rocks beneath the ground have started collapsing.
3. Water Puddles
If you find water puddles even when there is zero rain, chances are the area has poor drainage, and places like these are more prone to land sinking.
4. Slanting and Sinking Objects
If nearby structures like fences, trees, or utility poles are leaning or tilting more than usual, this could suggest that the ground underneath is sinking. Apart from that, if you have garden features like statues, birdbaths, or planters that seem to have sunk or tilted, it might be due to subsidence.
5. Change in Vegetation
Land sinking also affects plants. If plants that were once thriving start to show signs of stress, wilting, or dying, it might be due to changes in soil structure caused by sinking.
Why Lawn Sinks When You Walk on it?
There can be a lot of reasons why your lawn is sinking. Some are reversible and can be controlled, while others cannot. So before fixing your lawn, you should first understand why it is sinking and whether you should invest in the fixing job.
1. Soil Erosion
Soil erosion is a common phenomenon, and it happens when wind, water, or other forces gradually remove soil particles from the surface. It can lead to the gradual subsidence of the lawn as the soil layer gets thinner and less stable.
So notice if the spot is constantly being hit by natural forces like wind or manual watering, which could lead to random soil erosion, causing lawn sinking.
Watering your lawn is good; overwatering isn’t. If the water isn’t draining properly and getting clogged just under the topsoil, it can lead to soil compaction and sinking.
Apart from overwatering, there can be other reasons behind soil compaction.
Soil compaction happens when the soil particles are pressed tightly together, reducing pore space and water infiltration. It can result from heavy foot traffic, the presence of construction equipment, or poor soil management practices, causing the ground to sink over time.
4. Thatch Buildup
If the entire top layer of your lawn feels squishy rather than sinking or depleting in some spots, it can be due to thatch buildup. It is an organic material formed from dead grass and plant parts.
You can expect more thatch during the growing season if you have planted grass types like Kentucky bluegrass or creeping red fescue. It can make your lawn appear mushy to walk on.
5. Subsurface Water Stream
If your lawn has a subsurface stream, its excessive water movement can erode the soil from within and create voids, leading to land sinking. Poor drainage systems, leaking pipes, and even natural water streams can be some examples of such subsurface water streams.
6. Underground Caves and Voids
In areas with excess limestone or other soluble rocks, underground caves or voids can form due to the dissolution of these rocks by water. As the voids expand, the surface can sink abruptly.
7. Poorly Filled Ground
If your lawn was built on poorly compacted fill soil, it may settle unevenly over time, leading to sinking in some areas.
8. Fluctuating Groundwater Levels
Fluctuations in groundwater levels can affect the stability of the soil. When water levels drop, soil can dry out and shrink, leading to sinking.
9. Human Activities
Human activities like mining or excess groundwater extraction and oil and gas extraction can also create massive voids that can lead to land sinking on a large scale. So check whether your property has any mining history or has been built on abandoned mines.
However, there can be other more complex geological reasons, which can only be identified by experts. So you can consult a geotechnical engineer or soil scientist if the sinking keeps growing and you cannot figure out why.
How to Fix a Lawn that Sinks When You Walk on it?
If the problem is minor, like underground mines or subsurface natural streams, here are some things you can try to fix your lawn.
1. Fix the Drainage Issues
Drainage issues would be inevitable if your house is located in a lowland compared to your neighborhood. Try to regrade the land and ensure water flows away from your lawn.
Also, ensure no leaking pipes or drains are under your lawn’s subsurface.
2. Change the Soil Type of Your Lawn
If your lawn has more clay, it will lead to poor drainage and sinking issues. So, try to fix the soil composition by mixing more organic matter, sand, etc, with it.
3. Aerate Your Lawn
If the sinking is due to soil compaction, you can try aeration to improve the situation. It is the process of making small holes in the soil to loosen it. If you are curious about how to DIY the process, check out our article on how to aerate your lawn by hand.
4. Add Topsoil
Topsoil can be a quick fix, or you can add an extra protective touch to your lawn once you have fixed the real problem.
Adding more topsoil will fill the depression, balance out the clay component in your soil, and soak up excess water better.
Is a Sinking Lawn When You Step on it Alarming?
The answer to whether your sinking lawn is an alarming issue depends on why it is happening.
If the reasons are overwatering, compaction, and excess clay component, it is nothing big and can be fixed easily.
However, if the reason is something else and you see the sinking gradually increase, you need to have a thorough inspection done.
If only a few places in your lawn are sinking in a scattered way, it can happen due to drainage problems and need to be addressed.
However, it can be alarming if a fixed spot sinks and continuously grows in radius over time. It could indicate an underground void that can lead to a catastrophic and potentially life-threatening collapse.
Look for uneven surfaces, depressions, cracks, slanting structures, or sudden changes in vegetation health. Sinkholes, misaligned doors/windows, and pooling water can indicate a sinking lawn.
While minor issues like soil compaction can be addressed by homeowners, accurately diagnosing and remedying sinking requires professional expertise. Consulting geotechnical engineers or landscapers will be the best way to handle things.
Depending on the cause and severity, it’s often possible to reverse the process of a lawn sinking for whatever reason.
Solutions may include soil amendments, compaction relief, reseeding or sodding, and addressing underlying issues. A professional assessment is key.
Lawn sinking not only hampers your property’s aesthetics but can also indicate an underlying problem. So whenever you notice one, carefully diagnose the reason behind it. While drainage is the usual suspect for most cases, if you suspect something larger than that, fix it ASAP to avoid any safety hazards.
While dethatching and fixing soil composition should do the trick for smaller causes, bigger problems like underground mines and streams need a comprehensive solution and expert supervision.