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Our Story

Where it all began...

SESL Australia’s story starts with one man- Simon Leake, the sole founder of the company. 


Born in Perth, Western Australia to one of the first settlement families in WA, Simon moved to Sydney in 1967 attending Turramurra Public School then Turramurra High School.


Simons grandfather from Perth had travelled to the other side of the country and completed his leaving certificate at Hawkesbury Agricultural high school in Richmond. So from the age of 16, the thought of studying agriculture was cemented in his mind as a possibility. 

Simon was always good at biology and later in high school, he developed a keen interest in chemistry as well. Despite this, when time came to move on from high school, he wasn’t sure on his direction and chose to travel around Australia instead.

Stacked Books

University Life

Looking through the bulky “University Calendars” as they were called then, Simon came across “Bachelor of Agricultural Science” at Sydney Uni. This had a vast array of biology subjects including botany, plant and animal science, some economics, statistics chemistry, biochemistry… in fact agriculture was the perfect subject for someone who was unsure about direction.


When Simon graduated from uni, there were few suitable jobs in his field. So he had to make do and found himself adapting his knowledge into other available positions. Using his knowledge of chemistry, Simon began working with a leading pathologist in a research role, developing biochemistry tests for the new automatic analyser technology.

Founding SESL

Simon knew that the same extracting solutions he was using at work, could be used to understand the make-up and qualities of soil. The same chemistries used to detect phosphorus in blood for example, were used to test phosphorus counts in soil extracts. It wasn’t until someone took a chance on Simon however, that his full potential was realised. Encouraged by the pathologist Dr Colin Mansfield who long had an intrigue in agriculture (and vested interest in Simon due to his courtship with Dr Mansfield’s daughter), Simon began the plans to set up his own soil testing laboratory. 

Dr Mansfield registered the company name Sydney Environmental and Soil Laboratory (now known as SESL Australia) in 1983, and using all of his automatic equipment, Simon started setting up his methods. Even from the beginning, SESL Australia was unique to other labs- not only testing the soils, but providing advice and recommendations as well. Initially, Simon was advising farmers, nursery people and potting mix supplier, but then found his niche in the landscape and land development industry.

Simon AIH Awards night.jpg

Simon accepting the award for

Australian Institute of Higher Education (AIH)

 Horticulturalist of the year 2016

Since then

Simon has made a lifetime study of soils and their improvement to create healthy plant growth. SESL has seen just about every possible problem there is in soils that affect the growing of plants. 

Over the decades, Simon and SESL Australia have accumulated a wealth of knowledge on how to improve and rehabilitate soils. This includes the growing of plants of all different kinds including those adapted to rich highly fertile soils like vegetables and cut flower to those adapted to and needing low fertility soils. In fact, many of the Australian plants react badly to being planted in nutrient rich soils.

Some of the Landscape projects he has completed include:

  • Barangaroo Headlands

  • Darling Harbour & the Chinese garden - Sydney, Australia

  • Homebush bay & the Olympics 2000 - Sydney, Australia

  • Sydney Olympic Park - Sydney, Australia

  • King Salman Park - Saudi Arabia

  • Hornsby Quarry Park - Sydney, Australia

  • Royal Randwick Racecourse - Sydney, Australia

  • Bond University, The Gold Coast, Australia

  • Yularu resort, Uluru, Australia

  • Western Sydney Airport​, Sydney Australia

  • Tullamarine Airport Landscaping

  • Sydney Water ocean outfalls

  • COALEX Lithgow Coalmine revegetation

  • Sydney Water Biosolids application program

Some of Simon Leakes Publications 


Grow Your Own: How to be an Urban Farmer
By Angus Stewart & Simon Leake 

Soils for Landscape Development: Selection, Specification & Validation  
Simon Leake & Elke Haege 

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