More than 18,000 plants from the display are to be sold for a gold coin (orchids and other special plants will be $10).
All about Flowers is the first floral installation at The Calyx, the new horticultural display centre.
The money raised from the sale will support horticulture, conservation, scientific research and educations programs at the Royal Botanic Garden.
The Garden's Growing Friends Nursery will also be open for extended hours on Saturday. The Nursery stocks a range of native, exotic, rare and hard-to-find plants.
Where: The Calyx, Royal Botanic Garden Sydney.
When: 8am-2.30pm, 5 Aug 2017
How many: Limit of 5 orchids or special plants
For more information, go to The Royal Botanic Garden Sydney.