Seeing a lawn bubble in your yard can be alarming. These rarely pop up in residential settings but are commonly found on sports fields and golf courses. Now that you have one, however, do you need to treat this lawn blister or will it go away on its own? Will more of them form and can you prevent them? All of these questions and more are answered below.
What Causes Lawn Bubbles to Form? (The Short Answer)
How are lawn bubbles formed, in the first place? Lawn bubbles, aka lawn blisters, are formed when water gets trapped between your grass and the ground beneath it. For several reasons, this water cannot drain away and forms a small, visible hill or “bubble” within your lawn.
How to Tell If You Have a Lawn Bubble (Signs to Watch Out For)
Lawn bubbles have a fairly unique appearance but they can sometimes be confused with molehills, groundhog burrows, or ground that has seized or relaxed due to a sudden freeze or thaw. Below are several things you can look for so you know for sure that you have a grass bubble.
- Recent Heavy Rain, Burst Pipe, Leaking Septic System, or Ruptured Water Line – If any of these events have happened in the last 3 days or so, you are likely to have a lawn bubble.
- Plastic Sheeting Layered Under the Lawn – If you have plastic sheeting layered under your lawn, the chances that your lawn will develop a water pocket under the grass increase.
- Sudden Heat Wave After Long, Cold Winter – In some cases, especially in traditionally cold areas, a sudden heat wave after months of freezing, snowy weather can cause the top layer of the soil to become waterlogged while the layer beneath is still frozen. This will usually lead to an exceptionally large water blister.
- Uneven Turf – If you have a low spot in your lawn that water typically drains into and this is where your water bubble has formed under the lawn, this area needs to be evened out as soon as possible.
- Excessive Water Pooling Near the Suspected Lawn Blister – Sometimes water will seep out of a water blister and pool nearby, especially if you have grass with deep roots or grass that is patchy.
- The “Bubble” Rebounds When Disturbed – Lawn bubbles are often called “lawn waterbeds” and “water trampolines” because they wobble and spring back when stepped on.
- Water Floods Out When the Area is Punctured – The definitive way to know if you have a lawn bubble is by sticking a pipe into it or using a shovel to cut a wedge out of it. If it is a lawn bubble, water should flood out. If you are already nearly certain that you are dealing with a lawn bubble, you should wait until you have a drainage plan in place to take this step.
The Factors That Can Cause Lawn Bubbles
Eight main factors contribute to the formation of a lawn blister. You can learn what they are and why they’re important below.
Rapid Temperature Changes Can Create a Layer of Ice Preventing Drainage
If you live in a traditionally cold area and have had a snowing winter then a sudden thaw and heat wave can cause the top layer of your lawn to become waterlogged. The layer below this swampy situation is likely still frozen. As the water sits on top of the lawn, it may seep under the layer of grass and thatch, causing this layer to float and a water pocket to form.
Heavy Rain Can Cause Water to Fill Pockets Under Your Grass
Like with melted snow, direct heavy rainfall can cause pockets between shallow-rooted grass varieties and water-logged or heavy-clay soils.
Leaking or Broken Tanks and Pipes Can Rapidly Form Water Pockets
Overall, any source of excess water or other fluid can cause water pockets to form. A sudden flood from underground, in the form of a ruptured tank or pipe, can increase the chances of water pockets forming due to the volume and pressure involved.
Plastic Sheeting or Another Membrane With Improper Drainage
Plastic sheeting or any other material that creates a solid layer through which water cannot drain will increase the chances that water will build up in the soil underneath your lawn.
Drainage Holes Can Become Water-Logged
Over time, drainage holes or depressions in a lawn can become saturated with water while the rest of the lawn appears dry. If the grass in this area still grows well even though the soil is deeply saturated, eventually heavy rainfall will cause a water pocket to form.
Compacted Soil Can Prevent Water From Draining
The denser the soil is, the less water can pass through it, and the easier it will be for this soil to become saturated.
Heavy Clay Soils Impede Drainage
Like with compacted soil, heavy clay soil can create a layer that is so compact water has a hard time passing through. Water will then build up on top of this clay “floor” with nowhere to go but up creating a water bubble under your lawn.
Deep Roots Prevent Pockets from Forming
The deeper the roots of your grass are, the more likely water will be to settle above your lawn instead of beneath it.
How Are Grass Bubbles Formed?
Grass bubbles are formed when more water seeps into an area around or under your lawn than can be drained away. Either the surrounding terrain is already similarly saturated with water or a membrane, like plastic sheeting, is keeping the water in place.
The bubble is under the grass layer because grass cannot form a solid surface, though it can appear solid enough once the water has formed a bubble beneath and may only seep a small amount of water over time.
Are Lawn Bubbles Dangerous? – Can They Harm Your Grass?
Lawn bubbles are not dangerous to people beyond the slight chance of slipping or falling due to their unstable nature. However, water pockets under the grass can cause problems for your lawn.
Just like abnormally wet conditions or standing water, the biggest concern here is root rot or the growth of mold. Once the water bubble under your grass has been drained away, there is no additional cause for concern.
The single exception to this statement is a lawn bubble that was caused by a septic leak. Fluid and sludge from a septic leak should be handled by a professional and as much should be vacuumed up and hauled away as possible.
Septic fluid can cause permanent damage to your lawn and is a health hazard. The cleanup of this substance is not something you should attempt to do alone or without expert guidance.
How to Fix a Lawn Bubble (Here’s What I’d Do)
Fixing a lawn bubble is fairly simple and can improve the health of your lawn overall. Below are the 4 steps I would take to heal a water pocket I’d found in my lawn.
Evaluate and Correct Your Drainage Situation
Before anything else, you need to evaluate how well your lawn is draining and figure out what is preventing the water trapped in the lawn bubble from dispersing naturally. The list of factors in the section above should help you narrow down the cause.
Once you know the cause, create a plan to improve drainage. To avoid dealing with a mess of water on your lawn down the line, plan to pipe the water from the water bubble or lawn blister into a drain or ditch and away from your lawn.
Digging a drainage channel is often the fastest way to accomplish this.
Lance the Lawn Blister
Once you have your plan in place and you have a pipe or sharp shovel in hand, all you need to do is cut a hole into or press the pipe into the lawn bubble and watch the water drain away. Alternatively, you can use a suction device to vacuum the water. For smaller bubbles, a shop vac will do. For larger bubbles, you may need the help of a professional with a pump truck.
Clean Up The Excess Water On and Around Your Lawn
If any water escapes the drainage channel or system, now you should work on evenly distributing this water around your lawn as well as you can. A large push broom can come in handy here.
Fill in the Drainage Channel and Reseed the “Wound” in Your Lawn
Last, once the water has all been absorbed or sent away, it’s time to clean up the area. If there was anything else you wanted to do to improve the drainage of your lawn, now would be the time to do that.
Once all of your preventatives are in place, you should fill in any low spots in your lawn as well as any drainage channels you dug and the spot where the lawn water blister was lanced.
Finally, seed over these recently filled places to help your lawn resume its usual appearance as quickly as possible.
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