GardenSafe is our soil screening program. It aims to help gardeners stay safe and understand what makes up their garden soil. If you’re participating in GardenSafe or are looking for more information about what to expect, read on to demystify the science behind your results.

Once we’ve screened your soil, you’ll receive a report that details the results from your samples. This report provides a snapshot of the quality of your garden soil and if there are any common contaminants present. Your results can help guide your gardening practices to grow better veggies and make decisions about whether you need to take further action to protect your health. 

Register for GardenSafe to find out what's in your garden soil.

Garden soil quality indicators

As a part of your screening results, we’ll give you information about what your garden soil is made up of. Soil is a complex mixture of minerals, organic matter, gas, water and living organisms. These indicators help you understand the overall quality of your garden soil.  Ways of improving your soil quality include adding fertilisers, manure, or compost.

The garden soil quality indicators we screen for include:

  • Soil texture and composition – the proportion of sand, silt and clay. This can affect how your soil drains water and retains nutrients.
  • Total organic carbon - how much organic matter (such as leaf litter or compost) is in your soil.
  • Total phosphorous and potassium – can give an indication of how well your plants will grow.

Trace elements

Trace elements are a range of chemicals and minerals that may be present in your garden soil. Trace elements can come from many sources. Legacy chemicals from industry, leaded paint and petrol, and mining activities can all contribute to soil contamination.

At high concentrations, they may have harmful effects on human and environmental health. These contaminants include lead, arsenic and cadmium among others. We have listed some strategies that you can use to remove or reduce soil contamination. Removing or reducing soil contamination may require a combination of strategies.

Health Investigation Levels (HIL)

We compare your results against the Health Investigation Levels guideline for residential gardens with accessible soil (HIL A). These guidelines help identify when further investigation is recommended. If your results are above these guidelines, your garden soil may be contaminated. If this is the case, you may need a more detailed analysis. You can engage an environmental consultant who may:

  • conduct a site investigation,
  • collect samples and
  • submit them to a NATA accredited laboratory.

GardenSafe helps gardeners make informed decisions to protect their health and the environment. When you understand your screening results, you can enjoy a healthy and sustainable garden.

Remember to always follow safe gardening practices, such as wearing gloves and washing your hands, to minimise potential risks. Find out more and register for GardenSafe

Reviewed 1 November 2023