Garden Lime: When and How to Use It (and When Not To)

Garden lime is one of the oldest and most effective soil treatments, and one of the most misused.

What is garden lime?

Garden lime is ground limestone, a natural rock made mostly of calcium carbonate.

Why soil becomes acidic

Many soils are naturally acidic, especially in regions with high rainfall.

Step 1: Test your soil first

A soil test is the single most important step.

Step 2: Choose the right type of lime

Wood ash raises pH and supplies potassium, but its strength varies.

Step 3: Work out how much lime to apply

Always follow your soil test recommendation if you have one.

Step 4: Apply lime at the right time

It has to dissolve and react with the soil before the pH changes, which takes weeks to months.