Soil
Updated May 23, 2025
Soil pH testing
Best Practice
- Always prepare a soil-water slurry (soil mixed with distilled water) and dip the strip into the clear liquid portion for a reliable reading.
Here’s a quick protocol to test soil pH directly with pH strips, minimizing errors while skipping the slurry step:
Quick Direct Soil pH Test Protocol
|
Step |
Action |
|
1 |
Collect soil sample from 4–6 inches depth, mix multiple spots for representativeness |
|
2 |
Remove large debris, roots, stones, and break up clumps for fine soil consistency |
|
3 |
If soil is dry, moisten slightly with distilled water — just enough to make it damp (not muddy) |
|
4 |
Take a clean, dry pH strip and gently press it against the moist soil surface or slightly insert into soil for 5–10 seconds |
|
5 |
Remove strip and compare immediately to color chart provided with strips |
|
6 |
Repeat 2–3 times at different spots for average reading |
Notes
- Use distilled water to avoid altering pH.
- Avoid overly wet soil to prevent dilution of the strip reagent.
This method gives an approximate pH; for more precision, the slurry method or digital probe is preferred.
Slurry Method
|
Step |
Action |
|
1. Collect Soil |
Take a sample 4–6 inches deep from several locations in your bed. Mix well. |
|
2. Air-Dry (Optional) |
Let soil dry if excessively wet; do not oven-dry. Not necessary unless testing multiple times. |
|
3. Make a Slurry |
Mix 1 part soil with 2 parts distilled water in a clean container. (e.g., 1/2 cup soil + 1 cup water) |
|
4. Stir and Settle |
Stir thoroughly and let it sit for 15–30 minutes. Stir again before testing. |
|
5. Dip the Strip |
Insert a pH strip into the water (not the soil itself) for 1–3 seconds. |
|
6. Read Immediately |
Match color to the pH scale provided with your strips within 10–15 seconds. |
|
7. Record |
Average the readings if you test multiple spots. |
Accuracy Tips
|
Tip |
Reason |
|
Use distilled water |
Tap water may contain minerals that skew pH |
|
Test multiple areas |
Soil pH can vary widely across a garden |
|
Avoid testing after fertilizer application |
Wait at least 1–2 weeks to avoid misleading results |
Can I use pH strips directly on wet soil?
No, it’s not recommended to use pH strips directly on wet soil because:
- Soil particles can stick to the strip, causing inaccurate color changes.
- The moisture in soil is uneven, leading to inconsistent pH readings.
- Soil contains solids and organic matter that interfere with proper strip contact.
Interpreting pH Readings
| pH Range | Soil Reaction | Plant Suitability |
| 4.5–5.5 | Strongly acidic | Blueberries, azaleas, rhododendrons |
| 5.6–6.5 | Moderately acidic | Most vegetables, shrubs, fruit trees |
| 6.6–7.3 | Neutral | General-purpose gardening, turfgrass |
| 7.4–8.5 | Alkaline | Lavender, lilac, some grasses |
Mulch Areas **
Composition
Kiss the Ground (book and movie)
Related Links
US Government (National Weather Service) **
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