That bouncy, spongy feeling underfoot is not a sign of a healthy, lush lawn. It is a warning.
Buffalo grass is the highest thatch-producing lawn variety available, and thatch is the hidden layer of dead organic matter that builds up between your soil and your green grass blades. When it gets thick enough, water cannot penetrate, nutrients cannot reach roots, and your grass starts growing in dead material instead of soil.
The stakes are real: if you treat a spongy buffalo lawn the same way you would treat kikuyu or couch, you can kill it entirely. Buffalo has no underground runners to recover from aggressive dethatching. One wrong move and you are relaying turf from scratch.
This guide shows you the correct diagnosis, the only safe fix for buffalo specifically, and how to stop it from coming back.
What Makes a Buffalo Lawn Go Spongy
The culprit is thatch. Thatch is a tightly intermingled layer of living and dead stems, leaves, and roots that accumulates between the layer of actively growing grass and the soil underneath.
Buffalo lawns produce a series of thick-stemmed stolons or runners that create a thatch layer. When each new generation of stolons is produced, the new growth rises above the old, and over time, the roots no longer live in the soil but in the old thatch layer itself.
That is why your lawn feels spongy. You are walking on accumulated dead plant material, not firm soil.
How to Diagnose Your Thatch Thickness
Before you do anything, measure the problem.
Cut a small wedge-shaped plug from your lawn about 5 to 7cm deep. Pull it out and look at the brown layer sitting between the green grass blades and the soil surface. That brown mat is your thatch.
According to Oklahoma State University Extension, the thatch layer should not exceed half an inch (12mm) in warm-season grass lawns such as buffalograss. A lawn with excessive thatch will often feel very spongy.
Use that 12mm number as your threshold. Under it: monitor and adjust mowing habits. Over it: you need to act now with the method below.
Why Buffalo Is Different from Every Other Grass
This is the most critical thing to understand before you touch your lawn.
While some suggest vertimowing, de-thatching or scarifying as a process for removing thatch, this practice is not recommended for buffalo lawns. Buffalo grass does not possess the underground runners required for it to repair.
Direct Turf advises that homeowners identify their grass variety before attempting any thatch removal, since the wrong method on buffalo can cause irreversible damage with no underground root system to fall back on.
Kikuyu, couch, and zoysia all have rhizomes, which are underground stems that survive aggressive dethatching and push new growth back up within weeks. Buffalo only has above-ground stolons. Scalp those, and there is nothing left underground to regenerate from.
Buffalo grass has no underground runners and grows primarily from above-ground stolons. You cannot scarify a buffalo lawn under any circumstances.
If a landscaper quotes you for vertimowing your buffalo and cannot explain why that is dangerous, find a different landscaper.
The Safe Fix: Gradual Mowing Reduction
The correct approach is progressive. You lower the mowing height incrementally, cutting into the thatch layer a little at a time, while giving the lawn time to recover between sessions.
Step 1: Set your mower one notch lower than your current height
Do not drop two or three notches at once. Lower your mower one notch below your normal height, and always leave some green leaf behind. Do not remove all colour. Removing all green leaves exposes the brown thatch entirely, and the lawn cannot photosynthesise or recover.
Step 2: Wait 3 to 4 weeks
Wait until the lawn begins to show signs of green leaf growth and repair before mowing again. Do not rush this. Recovery time is not optional.
Step 3: Drop one notch again
Repeat the process. Each pass removes another layer of thatch without shocking the plant system. Most buffalo lawns only need to be dethatched every 2 to 3 years, depending on how quickly thatch builds up. However, if your lawn feels spongy when you walk on it or the thatch layer is more than 1.5cm thick, it is time to act.
Step 4: Hold your final mowing height
Buffalo grass should be maintained at a mowing height between 30mm and 50mm. For a spongy lawn, a mowing height of 50mm is ideal. For a less thatchy, tighter lawn, 30mm is recommended.
Timing matters
Never de-thatch during the heat of summer, as this could highly stress the lawn and may kill it. Begin de-thatching only at the start of spring or autumn.
What to Do After You’ve Fixed It
Once the thatch layer is back under 12mm and the lawn looks green and even, there are three things to do immediately.
Apply a slow-release fertiliser
After removing the thatch, use a slow-release fertiliser to encourage the lawn to thicken up again. Do not fertilise during the active repair period; wait until recovery is clearly underway.
Aerate the soil
Thatch suppresses the microorganisms that naturally break down organic matter. Good aeration, soil pH around 6.5, and adequate moisture favour the build-up and activity of beneficial microorganisms that prevent excess thatch accumulation. Core aeration restores that environment.
Adjust your watering depth
Shallow, frequent watering trains roots to stay near the surface inside the thatch layer. Deep, infrequent watering pushes roots down into the soil where they belong, reducing future sponginess.
What Causes Thatch to Build Up in the First Place
Understanding the cause stops the problem from returning.
Over-fertilising with nitrogen
Excessive watering or fertilising and improper mowing can cause turfgrass to develop a thick, spongy mat of thatch. High nitrogen pushes grass growth faster than the soil microorganisms can break the old material down. Use slow-release fertilisers and test your soil before applying.
Mowing too infrequently or too high
Letting the lawn grow long between mows produces long clippings that sit on top of the canopy rather than falling to the soil, where they can decompose. Mow little and often.
Over-fertilising with nitrogen again
Avoid over-fertilising. Too much nitrogen produces lush, spongy growth that directly contributes to thatch build-up. This point is worth repeating because it is the most common mistake homeowners make, thinking they are improving the lawn.
Compacted or acidic soil
Thatch problems are sometimes common in acidic and compacted soils since a healthy microorganism population does not flourish under these conditions. Get your soil pH tested if thatch returns quickly after treatment.
Buffalo vs Other Grasses: Thatch Treatment Comparison
| Factor | Buffalo | Kikuyu / Couch | Zoysia |
| Thatch tendency | Very high | High | Moderate |
| Recovery runners | Above-ground only (stolons) | Above + underground (rhizomes) | Underground (rhizomes) |
| Vertimowing safe? | No | Yes | Yes |
| Scarifying safe? | No | Yes | Yes |
| Dethatching method | Gradual mowing reduction | Vertimow or dethatcher | Dethatcher or rake |
| Mowing height range | 30 to 50mm | 15 to 30mm | 15 to 30mm |
| Dethatch frequency | Every 2 to 3 years (or when spongy) | Every 1 to 2 years | Every 2 to 3 years |
| Risk if done wrong | Full lawn death | Slow recovery | Moderate recovery |
When the Lawn Is Beyond Saving
Gradual mowing reduction works for moderate thatch. It does not work for every situation.
Before committing to a full relay, it is worth revisiting the natural turf vs artificial turf decision entirely, since a lawn that has thatched to the point of removal is a legitimate trigger to reassess whether buffalo grass is the right long-term surface for the space.
If you have a buffalo lawn that is severely thatched at 15cm or more, the lawn may need to be removed entirely and a new lawn installed. Before undertaking this process, before making that call, Direct Turf recommends getting a proper on-site assessment. A trained eye can tell whether the stolons still have enough soil contact to recover, or whether a full relay is the only viable path forward.
The visual signs of a lawn past recovery include: runners that have lifted completely off the soil surface, patches that have gone brown and do not green up after rain, and water that sheets off the surface entirely rather than soaking in. At that stage, the roots are living in dead material, and there is no soil contact left to save.
Conclusion
A spongy buffalo lawn is a thatch problem with one correct solution: gradual, staged mowing reduction done in spring or autumn, never with a vertimower or scarifier that will kill the grass it cannot regenerate from. Keep your mowing height between 30 and 50mm, water deeply rather than shallowly, hold back on nitrogen-heavy fertilisers, and aerate annually to keep the soil microorganisms that naturally decompose thatch working in your favour.
