An Australian study is helping beekeepers decide where to place their hives to collect valuable healing honey.
The research has found that Australian shrubs and trees can produce healing honey on a scale to rival New Zealand's prized manuka medicinal honey industry.
But it also reveals that not all of Australia's Leptospermum species of plants, which make healing honey, can equally produce large amounts with active antimicrobial properties.
New Zealand produces manuka medicinal honey from the plant Leptospermum scoparium, one of 84 Leptospermum species that are native to Australia.
On the hunt for liquid gold
At the University of the Sunshine Coast's honey laboratory, PhD candidate Simon Williams is testing hundreds of samples of nectar and honey produced by Leptospermum shrubs and trees sent by professional and amateur beekeepers around Australia.
Mr Williams has been mapping the distribution of Australia's Leptospermum species. He is also assessing how much nectar the plants produce and their bacteria-fighting abilities.
Beekeepers use the information to decide where to position their hives.
Mr Williams is part of the Oz Honey Project, which is examining the antibacterial potential of Leptospermum honey for medicine, as well as the honey's other healing and anti-inflammatory properties.
The project also involves researchers from the University of Technology Sydney and the University of Sydney, and is jointly funded by government and industry.
"For the past three years I've tested 54 of the species to determine which ones beekeepers should target," Mr Williams said.
"South-east Queensland, [including] the Sunshine Coast, and New South Wales northern rivers definitely have some of the stronger species and seem to give a more continuous honey production, which is beneficial to know."
Not all Leptospermum trees and shrubs are equal
Just as not all of the 84 Leptospermum species in Australia equally produce honey, the same applies to their medical potential.
"It's definitely quite varied," Mr Williams said.
"The nectar provides the dihydroxyacetone [DHA] which is the precursor to the medical properties in the honey.
"The New Zealand Leptospermum scoparium is about middle of the range DHA.
"In Australia, we have species ranging from no DHA in their nectar, like Leptospermum laevigatum or coastal tea tree, to very high levels of 20-30 parts per million in Leptospermum polygalifolium and Leptospermum speciosum and whitei.
Secrecy surrounds plantations
In a secret location on the rich soils of the Blackall range, Chris Johnson has watched his small but thriving Leptospermum plantation grow as tall as two metres in two years.
The publicity officer for Sunshine Coast Beekeepers planted 850 trees and hopes to harvest medicinal honey from them.
"I've got two varieties: Leptospermum polygalifolium, which is the common jellybush, and Leptospermum petersonii, which is a mountainous variety," Mr Johnson said.
Last year the flowers flushed during a desperately dry spring. When the honey produced was tested, it did not have the antimicrobial bacteria fighting abilities Mr Johnson had hoped for.
"I think it depends on the growing conditions at the time and how much nectar is in the plants."
Mr Johnson hopes researchers will be able to pin down what makes the nectar and honey so variable.
"You'll get variations from one bed to the other. It's a matter of getting the plants right. Weather conditions [are a factor] I think," he said.
Mapping Leptospermums
With a growing market for Leptospermum plantations, Mr Williams has promised to keep the location of beekeepers' shrubs and trees confidential.
"Specific locations are obviously kept hidden," he said.
"But we've recently published two Leptospermum identification guides and they all have rough location maps to give people an idea of where [certain] species might be and how to identify those species so they can know what they have in their backyard."
It is a dramatic turnaround for the honey which Australian apiarists used to spurn and even bury in holes.
"I've had people tell me where they used to not go to get honey because they'd get the Leptospermum honey, which is darker and stronger tasting. It's also jellylike," Mr Williams said.
"It forms a jelly in the honeycomb and that makes it a lot harder to extract so it's a lot of effort and time and it used to not be valuable at all.
