What Is Soil pH?
Soil pH measures how acidic or alkaline your soil is on a scale from 0 to 14. A pH of 7.0 is neutral. Most turfgrasses perform best in a slightly acidic range, roughly 6.0 to 6.8.
When soil sits outside this range, nutrients can still be present in the soil, but the lawn cannot absorb them properly. This is one of the most common reasons fertilisers appear ineffective, even when high quality products are being used.
If pH is wrong, the problem is not what you are applying. It is what the roots are able to access.
Why pH Matters for Nutrient Availability
Soil pH directly controls which nutrients are available to your lawn at any given time.
When pH drifts too far in either direction:
• Iron, manganese, zinc, and copper become unavailable in alkaline soils, leading to pale colour and chlorosis
• Phosphorus becomes locked up in both acidic and alkaline extremes
• Calcium and magnesium availability drops in acidic soils
• Nitrogen efficiency is reduced when root function is impaired
This means even a well planned fertiliser program can fail if soil chemistry is working against it.
| Nutrient | Becomes unavailable when | What you see |
|---|---|---|
| Iron, manganese, zinc, copper | The soil is alkaline | Pale colour and chlorosis |
| Phosphorus | Either extreme — acidic or alkaline | Locked up in the soil, so root and establishment response is poor |
| Calcium and magnesium | The soil is acidic | Availability drops |
| Nitrogen | Root function is impaired at either extreme | Reduced efficiency — applied, but not used |
Signs Your Soil pH May Be Off
You may be dealing with a pH issue if you notice:
• Fertiliser applications have little or no visible effect
• The lawn stays pale despite nitrogen or iron use
• Inconsistent performance across the lawn
• Moss, weeds, or excess thatch developing alongside weak turf
• Use of bore water or recycled water, which is often alkaline
These issues often show up gradually, which is why pH problems are commonly overlooked.
How to Check Your Soil pH
The simplest option is a home soil pH test kit, available from most garden or hardware stores. These are accurate enough for general lawn care decisions.
For more detailed insight, a professional lab soil test can confirm pH alongside nutrient levels and buffering capacity.
Tip: Test multiple areas of your lawn. Shaded zones, high traffic areas, and irrigated sections can all have different pH readings.
Adjusting Soil pH Carefully
Correcting pH takes time and should always be done gradually.
• To raise pH and reduce acidity, apply agricultural lime or dolomite
• To lower pH and reduce alkalinity, use elemental sulphur or ammonium-based fertilisers
Changes typically take weeks or months to show results. Overcorrecting can create new problems, so soil testing before and after adjustment is essential.
How The Lawn IQ Accounts for pH
Soil pH is a quiet performance limiter. That is why The Lawn IQ considers location, turf type, irrigation source, and known regional soil trends when building each plan.
Where pH risk is likely, programs include nutrient forms that remain more available under challenging conditions, alongside targeted micronutrients to support colour and growth while longer-term corrections are underway.
When soil chemistry works with your lawn instead of against it, everything else starts to fall into place.
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