The sculptures, standing up to four metres high, were created by artist Tom Hare and depict a conker, poppy seed heads, star anise, sycamore seed and a sacred lotus seed head.
The pieces form a sculpture trail around different parts of the garden. Wild flower sculptures by the same artist were installed in a different part of the estate last summer.
Head of Wakehurst Andy Jackson said the sculptures would enable visitors to take a closer look at the structures of seeds.
"We have placed the sculptures in locations where they link in with their natural surroundings," he said.
"Visitors can go on to find out more about the vital importance of seeds and the work being carried out to safeguard the world’s most endangered species at Kew’s Millennium Seed Bank which is located here at Wakehurst."