Resources to identify plant health problems

Many online resources exist that can assist you to determine if your plant(s) has damage potentially caused by a pest or plant disease.

We do not encourage using pictures to accurately diagnose plant health problems; however, they may be useful as a general guide to indicate if pathogens may be involved. If you suspect an exotic plant pest or disease, phone the Exotic Plant Pest Hotline on 1800 084 881.

You can use the following online resources to help identify the potential causes and determine if the problem warrants diagnostic testing.

Online and print resources and tools

  • A-Z list of significant pests and diseases
  • eResearch Archive (eRA) of scientific and research publications has many resources available to assist industry and the public. Search for the crop plant you are interested in using general descriptive terms.

    Agrilink information kits – eRA also holds kits for a variety of crop plants that includes information about their pests and diseases. Use the search term 'agrilink' to get a complete listing. Some industries have many resources available so you may need to check through all the results pages. View some of the kits currently available:
    • avocado
    • brassica crops
    • cashew
    • chilli/capsicum
    • citrus
    • macadamia
    • mango
    • ornamental plants
    • pawpaw
    • persimmon
    • rockmelon/honeydew
    • sweet corn
    • tomato
    • wildflowers.
  • NGIQ Pest Identification Tool is a free database that includes photos of pests and diseases that may impact garden and horticultural crops and pests. The tool is compatible with any web-enabled phone, tablet or computer. Registration is simple and free.
  • Nursery production pest and disease fact sheets, pest management plans and webinars are often relevant and have valuable information to assist you to understand key pests and diseases, and how to manage them.
  • Gardening Australia provides practical, realistic and credible horticultural and gardening advice.
  • Australian and overseas online resources and books may be available or can be requested from your local library or bookshop, often containing detailed photographs of pests and or diseases. Some of these include:
    • Crawford, D 2015, Garden pests, diseases & good bugs, HarperCollins Publishers Australia, Sydney, NSW, Australia, and ABC Books.
    • Hockings, D 2014, Pests, diseases and beneficials: friends and foes of Australian gardens, CSIRO Publishing, Collingwood, Victoria.
    • Cooke, T, Persley, DM, and House, S 2009, Diseases of fruit crops in Australia, CSIRO Publishing, Collingwood, Victoria
    • Cooke, T, Persley, DM, and House, S 2009, Diseases of vegetable crops in Australia, CSIRO Publishing, Collingwood, Victoria.

Search tips to find reliable information

Some plant species have a lot of information available online to assist diagnosing plant health problems, particularly commonly grown horticultural crops. Many ornamental plant species also have information available online, particularly overseas through university extension services in the USA.

When searching for information, consider the following sources:

  • Australian Government, state governments, industry and USA university extension services should be trusted more than home garden forums
  • scientific journal articles are increasingly available online and can be easily accessed by searching with Google scholar or similar services
  • fact sheets and websites that provide scientific references are generally more reliable than those without.

Exact search terms can often make a difference to the results you obtain. Start by using general terms and then make your search more specific as required.

Improve your search by:

  • using the genus name of the plant in question, add the species name if necessary, but this can limit the search too much
  • including 'disease', 'pest' or 'disorder’ in the search. Other phrases that can be useful to include are 'nutrient deficiency', 'non-pathogenic', 'best management growing' or 'production guide'
  • including more specific symptoms if known, for example, 'root rot', 'leaf spot', 'wilt', 'canker', 'camellia disease', 'palm borer' or 'tomato root rot'
  • taking care when completing image searches as these can be misleading. Always visit the site hosting the image to make sure that it is actually relevant and looks reliable.

Grow Help Australia and homeowners

Grow Help Australia is a pest and disease diagnostic fee-for-service service for commercial horticultural businesses where multiple plants are impacted, making the cost of the service economically viable.

By contrast, most homeowners have very few plants of any one type, so testing for the exact species of pest or pathogen present is very costly. In these situations, it is often more economical to remove the plant(s) and start again.

If your garden has large trees showing signs of dieback, the most common remedy is to provide optimal growing conditions. If the tree is structurally unsound, contact an arborist for professional, on-site advice. Some arborists and home garden services are also experienced in diagnosing tree pests and diseases. Such services are recommended for home gardeners. Grow Help Australia does not undertake home visits.