Soil pH Testing — Indicator Solution Method
Test your soil pH using a liquid indicator solution and colour chart. Quick, affordable, and accurate enough for garden decision-making. Results guide lime or sulfur amendments.
Version History
Version 1.0 Current
Effective: 2026-03-24Initial version
Procedure Details
The indicator solution may stain skin and clothing. Avoid contact with eyes. Wash hands after use.
You will need:
- Soil pH test kit with indicator solution and colour chart
- Clean jar or test tube
- Distilled or rainwater (tap water may affect results)
- Trowel for sampling
- Paper and pen to record results
Procedure Steps (Version 1.0)
Collect soil from 5-10 spots across the bed or area you want to test, at 10-15cm depth. Avoid surface mulch and debris.
Mix all samples together in a clean container to create a composite sample. Break up any clumps.
Place a teaspoon of soil in the test tube or jar provided with your kit.
Add distilled or rainwater to the fill line. Shake or stir gently.
Add the indicator solution according to kit instructions (usually a few drops).
Wait for the colour to develop (usually 30-60 seconds). Compare against the colour chart.
Record the pH reading, the date, the bed/zone tested, and any notes about recent amendments or conditions.
Repeat for each distinct area of your garden (different beds, zones, or soil types may vary).
Interpret results: most vegetables prefer pH 6.0-7.0. Blueberries prefer 4.5-5.5. Native Australian plants often prefer 5.5-6.5.
If pH adjustment is needed, apply lime to raise pH or sulfur to lower it. Retest in 4-6 weeks. Record all amendments applied.