Manuka honey is produced by bees from the nectar of the Leptospermum bushes. The Leptospermums are native to Australia, with many endemic species found nowhere else in the world. Australia is home to 84 of the 87 known Leptospermum species worldwide, including the famed Leptospermum Scoparium which is believed to have travelled to New Zealand from Australia some time in the last 20 million years.
A recent 5-year study by the University of Technology Sydney, Sydney University, and the University of the Southern Cross, found that the level of the major active ingredients in Manuka Honey in seven of the Australian Leptospermum samples tested, was comparable to or up to four percentage points higher than those observed in the UMF15+ comparator NZ Manuka Honey.
The study indicates that the strength of Manuka Honey is determined by a variety of factors, including the Leptospermum species, soil and climatic conditions.