Birmingham Botanical Gardens is once again going head-to-head with botanical gardens from around the world in the fourth edition of Denver Botanic Gardens’ annual Waterlily Weigh-Off, and this year it has a new giant contender in the pond.
The playful global competition, organised by Denver Botanic Gardens, sees botanical gardens, zoos, parks and museums put their giant Victoria waterlilies to the test to see how much weight a single waterlily leaf can bear before it sinks. The 2025 competition attracted more than 40 participants from nine countries, with Florida’s Bok Tower Gardens taking the title after its waterlily supported 83kg. This year’s competition categories include the Lightweight and Heavyweight Waterlilies, as well as a ‘Fan Favourite’ voted by viewers.
Following last year’s entry, which saw a Victoria cruziana waterlily measure 135cm and weigh 34.2kg, Birmingham Botanical Gardens is returning to the international challenge with a Victoria ‘Longwood Hybrid’, hoping to grow an even bigger and stronger contender.
While the competition provides a unique initiative, Birmingham Botanical Gardens’ relationship with giant waterlilies stretches back more than 170 years.
The Gardens’ Tropical House, formally known as the Lily House, was built in 1852, complete with a 24-ft-diameter circular pool. The build was prompted by a Victoria giant lily gifted from Joseph Paxton, head gardener to the Duke of Devonshire at Chatsworth.
The Lily House has since undergone many renovations, being rebuilt in 1904 with improvements made to the pool and heating system to create the conditions needed for giant waterlilies. In 1977, it was reconstructed to its original design and renamed the Tropical House which represented tropical regions from around the world with economic plants including bananas, sugar cane, cacao, yams, and vanilla; many of which can still be seen in the glasshouse today.
Further work took place in the early 1990s, including the installation of a new, raised and double-glazed roof, improvements to ventilation and a complete reconstruction of the pool, made possible by community raised funds.
The temperature of the lily pond has since been raised to 25 degrees and the water dyed black to prevent algae from choking the light needed for the giant lily pads to grow.
Now, as Birmingham Botanical Gardens continues its major multi-million pound Growing Our Green Heritage Project, the return of the giant waterlily represents another chapter in the building’s long horticultural history. As part of the historic glasshouse restoration project, the Tropical House will be reverted back to its original name of ‘Lily House’.
Alberto Trinco, Senior Glasshouse Horticulturist, at Birmingham Botanical Gardens said, “Giant waterlilies have fascinated visitors here for generations, dating all the way back to the 1850s, so we’re excited to be taking part in the competition once more.
“Last year’s 34.2kg waterlily was a fantastic achievement, but this year we’re hoping our Victoria ‘Longwood Hybrid’ can grow bigger and stronger. The competition is a wonderful opportunity to showcase just how remarkable these plants are and to share some of the horticulture skills that go into growing them.”
The Denver Waterlily Weigh-Off brings together private and public gardens across the world in a celebration of horticulture, science and the impressive strength of the waterlily. The winning heavy-weight waterlily will be announced on 26th August 2026.
To see all entries, the public can follow the competition on the dedicated Instagram page @WaterlilyWeighOff and see updates from Birmingham Botanical Gardens at @bhambotanicalgardens.
To find out more about Birmingham Botanical Gardens visit, https://birminghambotanicalgardens.org.uk/