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Soil pH Guide 🧪
Not all soil is the same — and different plants need different soil types. The pH scale measures how acid or alkaline your soil is.
A lower pH means more acidic, a higher pH means more alkaline, and a pH of around 7 is neutral.
Most garden plants prefer a slightly acidic to neutral soil (pH 6.0–7.0).
Move the slider to your soil's pH level to discover which plants will thrive in your garden.
Move the slider to your soil's pH level to discover which plants will thrive in your garden.
🧪 What pH is your soil?
4.04.55.05.56.06.57.07.58.08.5
← Strongly Acid
Neutral
Alkaline →
6.5
Slightly Acidic — Ideal for most plants
The sweet spot for most vegetables, grass, and general garden plants. Most nutrients are readily available at this pH.
Plants for pH 6.5
Plant name ★
Ideal pH — thrives at this level
Plant name
Suitable — tolerates this pH but not its optimum
Understanding Soil pH
🌿 Why pH matters
Soil pH controls the availability of nutrients. Even if nutrients are present, plants can't absorb them if the pH is wrong. Chlorosis (yellowing leaves) is a common sign of pH-related nutrient lockout.
🔴 How to lower pH (make more acid)
Add sulphur, acidic mulches (pine bark, ericaceous compost), or water with collected rainwater. For ericaceous plants in containers, use ericaceous compost. Changes take time — test regularly.
⬜ How to raise pH (make more alkaline)
Add garden lime (calcium carbonate) or dolomitic lime. Apply in autumn, at least 6 weeks before adding fertilisers. Never add lime and fertiliser at the same time — the reaction reduces both.
🧪 How to test your soil pH
Use an inexpensive soil pH test kit from any garden centre. Test several spots in your garden as pH can vary. For accuracy, test when soil is moist but not waterlogged, and test again after treatment.