Plant Doctor Pty Ltd
Shopping Cart 0
  • Grow Zone

      Lawns

      Gardens

      Farms
  • Fertilisers
  • Soil Health
  • Iron Rich
  • Weed & Pest
  • Bundles
  • Equipment
  • Health
  • Pets
  • Vouchers
  • Sale
  • Wholesale

      Register for Wholesale Pricing

      Buy in Bulk - Pallets, 200L, 1000L
  • Resources

      About Us

      Application Rates Calculator

      News

      Gallery

      The Periodic Table of Plant Nutrition

      Blog

      FAQ

      Product Usage Guide

      SDS
  • My Account
  • Home
  • Agriculture, Horticulture and Hydroponics
  • Lime Granules 1-2mm Slow Release 20 kg
Lime Granules 1-2mm Slow Release 20 kg

Lime Granules 1-2mm Slow Release 20 kg

Soil pH Balancer & Calcium Soil Conditioner

Lime Granules (calcium carbonate) raise soil pH by reducing acidity, improving nutrient availability and reducing toxic elements. Enhances soil structure, boosts microbial activity, and supports stronger roots and healthier lawns, gardens and pastures.
Calcium Carbonate (CaCO₃) Raises Soil pH & Nutrient Availability Fixes Acidic Soil Lockout
Lawns Gardens Farms
$65.00
In Stock
Write A Review
size

Notify me when back in stock

  • Description
  • Features
  • Specifications
  • How it Works
  • Application
  • Safety
  • FAQ
  • Reviews
  • Warranty
  • Shipping

Description

Correct Soil Acidity & Unlock Better Growth

Healthy soil starts with balanced pH. Agricultural Lime (Calcium Carbonate – CaCO₃) is a simple, highly effective soil conditioner designed to neutralise acidic soils and restore optimal growing conditions for lawns, gardens, and crops. By lifting soil pH, agricultural lime helps unlock nutrients that would otherwise be locked away, improving plant performance from the ground up.

Use Lime Granules when soil tests show low pH (acidic soil), before planting or establishing lawns and crops, and/or as part of seasonal soil improvement programs. Typically applied in autumn or early spring for best results.

Nutrient Profile: 

Ca
Calcium
 
CO₃
Carbonate
 

Why choose Lime Granules:

  • Raises soil pH by reducing acidity
  • Improves availability of key nutrients (N, P, K)
  • Supports stronger root development and plant growth
  • Enhances soil structure and aeration
  • Boosts beneficial microbial activity in soil
  • Reduces toxicity from elements like aluminium and manganese
  • Improves fertiliser efficiency and uptake
  • Suitable for lawns, gardens, and broadacre farming
  • Overall, agricultural lime is an essential tool in agriculture, helping to correct soil pH and create optimal growing conditions for a variety of crops. 

Agricultural lime restores balance at the foundation level, creating the right conditions for stronger roots, better nutrient uptake, and healthier, more productive growth across lawns, gardens, and farms.

(LIME_20)

Features

Lime granules are considered a soil Soil pH correction + calcium conditioning mineral, it does not feed plants directly, instead it:

  • Raises soil pH (reduces acidity)
  • Improves availability of nitrogen, phosphorus, and potassium in acidic soils
  • Reduces acid toxicity (aluminium and manganese issues)
  • Improves soil microbial activity and nutrient cycling
  • Enhances soil structure over time (especially in clay and compacted soils)
  • Provides a slow, long-term calcium source

Specifications

Technical Highlights
Active Ingredient: Calcium Carbonate (CaCO₃)
Primary Function: Soil conditioner for pH correction
Nutrient Efficiency: Improves nutrient availability and fertiliser efficiency
Supports Soil Biology: Enhances microbial soil life
Suitable Soil Types: Suitable for sandy, loam, and clay soils
Long-Term Benefits: Long-term soil improvement product
Key Nutrients:
  • Calcium (Ca) (as calcium carbonate, CaCO₃)
  • Carbonate (CO₃): balance component of limestone structure
Functional Composition:
  • Agricultural lime (calcium carbonate rock)
  • 1–2mm slow-release granular prill
  • Natural crushed limestone base
  • Non-soluble mineral that reacts gradually with soil moisture and acidity
Derived From: Natural crushed limestone (calcium carbonate rock)

How it Works

The Science Behind Lime:

Agricultural lime is primarily made of calcium carbonate (CaCO₃), which reacts with acidic soils to neutralise hydrogen ions and raise pH levels.

  • Acidic soils reduce nutrient availability and restrict plant growth
  • Lime neutralises acidity, creating a more balanced soil environment
  • Improves availability of essential nutrients such as nitrogen, phosphorus, and potassium
  • Enhances microbial activity, supporting natural nutrient cycling
  • Reduces solubility of toxic elements like aluminium and manganese in acidic soils
  • Calcium supports strong cell walls and root structure development

By correcting soil pH, agricultural lime helps restore the natural biological and chemical balance of soil. 

Application

The amount of agricultural lime needed to raise the pH of soil by 1 unit (e.g., from pH 5.5 to pH 6.5) depends on several factors, including:

  1. Soil Type: Sandy soils generally require less lime than clay or loamy soils because they have lower buffering capacity.
  2. Soil Texture: Clay soils, which have more surface area and higher buffering capacity, need more lime than sandy soils to achieve the same pH change.
  3. Soil Buffering Capacity: Soils with a high content of organic matter or minerals like iron, aluminum, or manganese can resist changes in pH and require more lime.

Application rates vary depending on soil type and conditions. Always perform a soil test before application to determine exact requirements.

Soil Type Application Rate Important Considerations:
Sandy soils ~50–75 g/m² per 1 pH increase
  • Soil Testing: It's important to conduct a soil test before applying lime. The test will provide specific recommendations based on your soil's current pH and nutrient levels.
  • Application Frequency: Lime should be applied in a manner that allows it to gradually alter the soil pH. Applying too much lime at once can cause sudden changes that may harm crops.
  • Method of Application: Lime should be evenly spread across the soil surface and, if possible, incorporated into the soil for better results.
Loam soils ~75–100 g/m² per 1 pH increase
Clay soils ~100–150 g/m² per 1 pH increase
Example If you are applying lime to a loam soil, you would need about 75–100 grams of agricultural lime per square meter to increase the pH by 1 point.

Safety

Safety Guidelines

Apply evenly across the soil surface and water in well after application. Avoid over-application, as excessive pH changes can reduce nutrient availability. Store in a cool, dry place and keep sealed when not in use.

FAQ

What are Lime Granules used for?

Lime Granules are a slow-release agricultural lime (calcium carbonate) designed to raise soil pH, reduce soil acidity, and improve nutrient availability. They're ideal for lawns, vegetable gardens, ornamental gardens, orchards, and broadacre farming where acidic soils are limiting plant growth.

How do Lime Granules improve soil?

Lime Granules neutralise acidic soils by gradually increasing soil pH. This unlocks nutrients such as nitrogen, phosphorus and potassium, encourages beneficial soil microbes, improves root development, and creates a healthier environment for plants to thrive.

How do I know if my soil needs lime?

A soil test is the best way to determine whether your soil is acidic. Signs of acidic soil can include poor plant growth, yellowing leaves, poor fertiliser response, moss in lawns, and reduced crop performance. Applying lime without testing may result in over-correcting soil pH.

Can I use Lime Granules on my lawn?

Yes. Lime Granules are excellent for Buffalo, Couch, Kikuyu and other lawn varieties growing in acidic soils. Correcting soil pH improves nutrient uptake, fertiliser efficiency, root development and overall lawn colour and density.

Are Lime Granules suitable for vegetable gardens and fruit trees?

Absolutely. Lime Granules can be used around vegetables, herbs, fruit trees, ornamentals and garden beds where soil acidity is reducing plant performance. Correcting soil pH helps plants make better use of available nutrients.

How long do Lime Granules take to work?

Lime Granules begin reacting once they come into contact with moisture and acidic soil, but because they are a slow-release product, soil pH changes occur gradually over weeks and months. This provides long-lasting soil improvement rather than a rapid temporary change.

Should I water Lime Granules after application?

Yes. Watering after application helps activate the granules and allows them to begin reacting with the soil. Where possible, lightly incorporate the granules into the topsoil for even faster results.

When is the best time to apply Lime Granules?

Autumn and early spring are generally the best times to apply Lime Granules, giving the product time to gradually adjust soil pH before periods of active growth. However, they can be applied whenever soil testing indicates acidic conditions.

Will Lime Granules replace fertiliser?

No. Lime is a soil conditioner rather than a fertiliser. While it provides calcium, its primary role is to improve soil pH so plants can utilise existing nutrients and fertilisers more efficiently.

Can Lime Granules be applied with fertiliser?

Yes. Lime Granules complement most fertiliser programs by improving nutrient availability and reducing nutrient lock-up in acidic soils. Many gardeners apply lime as part of an annual soil improvement program alongside seasonal fertilising.

Are Lime Granules suitable for clay, sandy and loam soils?

Yes. Lime Granules can be used on sandy, loam and clay soils. The application rate will vary depending on soil type, current pH and buffering capacity, which is why soil testing is strongly recommended before application.

What is the active ingredient in Lime Granules?

Lime Granules are manufactured from natural crushed limestone and contain Calcium Carbonate (CaCO₃). They provide a long-term source of calcium while gradually correcting soil acidity.

Reviews

Be The First To Review This Product!

Help other Plant Doctor Pty Ltd users shop smarter by writing reviews for products you have purchased.

Write a product review

Warranty

90 Day Money Back Guarantee

Shop with confidence knowing your purchase is backed by our 100% 90-day money back guarantee. If you're not completely satisfied, simply contact us within 90 days for a refund.

Shipping

Calculate Shipping

Money Back Guarantee

Money Back Guarantee

Put your mind at ease with our 100% 90 day money back guarantee

Australian Owned

Australian Owned

Australian family owned and operated. Online sales since 2009.

Flat Rate Shipping

Flat Rate Shipping

Flat-rate shipping from $9.95* Fast and affordable!

$9.95 orders under 1kg/1L • $14.95 orders up to 50kg • $49.95 orders over 50kg. Does not include express. Some location exclusions apply.
View shipping policy for more info

FAST Dispatch

FAST Dispatch

Quick and reliable dispatch Australia-wide*

*Monday - Friday (Excludes Public Holidays)

Customer Reviews

First time owning lawn. Gave the team at plant doctor a ring and they supplied me with a wealth of information. Products turned up quickly.

Billy Green

Will definitely be getting more 8 weeks difference been using stimulizer, activ8mate, soil wetter, seaweed secrets and champion fertiliser. Was super fast delivery.

Michael Preddy

Only have great things to say about Plant Doctor. Organic products and a competitive price, fast shipping and easy to contact with questions. Have had great results with the special mix for lawns, and my plants (indoor and outdoor) love the seaweed secrets. I am excited to test out some of the animal products soon!

Tim McAuliffe

Plant Doctor

Sign-up for exclusive deals and the latest news.

Website

  • Plants and Lawns
  • People
  • Animals
  • On Sale
  • Manufacturing

Service

  • HOLIDAY NOTICE
  • My Account
  • Track Order
  • Resolution Centre
  • Become A Trade Partner

About Us

  • About Us
  • Our Blog
  • Contact Us
  • Freeze-Drying

Information

  • Terms of Use
  • Privacy Policy
  • Returns Policy
  • Security Policy
  • Shipping Policy
© 2026 Plant Doctor. All Rights Reserved.
Apply Filters