This summer, The Arboretum at Penn State entered the annual Waterlily Weigh-Off for the first time! Led by Denver Botanic Gardens, public gardens around the world compete for whose giant waterlily (Victoria spp.) can hold the most weight.
Here at the Arboretum, you can find our prized competitor, the Santa Cruz waterlily (Victoria cruziana), dominating the waters of the Oasis Garden’s central pool. This South American goliath is one of three species of giant waterlily, often referred to as water-platters. With leaves up to 6.5 feet in diameter, V. cruziana is the baby of the genus Victoria; V. amazonica and the even larger V. boliviana can grow leaves up to 10 feet in diameter. The famed ‘Longwood Hybrid’ cultivated variety, a hybrid between V. amazonica and V. cruziana, is also a popular choice for botanical gardens. Victoria ‘Longwood Hybrid’ rivals V. amazonica in size and was bred by Pennsylvania’s very own Longwood Gardens in 1960. Past competitors in the Waterlily Weigh-Off have reached over 150 pounds on a single leaf with this cultivar! Victoria ‘Longwood Hybrid’ also previously took the spotlight in our Oasis Garden in 2021. We could see a return of this behemoth in future years, but it would leave very little room for many of our other favorite aquatic plants in the pool! This summer, our V. cruziana is nestled between smaller waterlilies and lotuses—many colorful Nymphaea (waterlily) and Nelumbo (lotus) cultivars. If you’re curious about all the plants in our pool this season, then make sure you check out our seasonal plant list!
These giant waterlilies support immense weight, like Weigh-Off demonstrates, due to a network of sturdy (and sharp!) ribs crisscrossing the bottom of their leaves. Areas of thin and slightly convex tissue bisect this sprawling network, trapping air bubbles between the ribs and causing the leaves to be remarkably buoyant. When weight is administered, stiff upright rims further prevent leakage. These upright edges are also thought to prevent other plants from encroaching on its territory, and Victorias have even been known to shred the leaves of their neighbors. Now that you know the incredible weight-bearing potential of our Santa Cruz waterlily, please leave the buoyancy testing to our weigh-off professionals and avoid putting objects on the lily pads—we don’t want damage the plants, or retrieve your phone, wallet, or wedding ring from the bottom of the Oasis pool!
Denver Botanic Gardens started the Weigh-Off to test the limits of their giant Victoria in 2023. By 2024, 17 gardens were participating. Missouri Botanical Garden in St. Louis, Missouri, took the crown with 142.1 pounds before their leaf collapsed. The competition went viral on social media, and by 2025, 48 gardens joined, with entries ranging from 0.02 pounds to the winning 183 pounds from Bok Tower Gardens in Lake Wales, Florida. This year, the competition is growing even further, with competitors from at least fifty public gardens, zoos, parks, and museums. Tere are even commercial nurseries and home growers entering the ring.
Submissions by video to the Waterlily Weigh-Off will be posted online between August 17 and 27 on social media. You can find The Arboretum at Penn State’s performance, as well as other gardens’, at @WaterlilyWeighoff on Instagram. The Arboretum’s horticulture staff, who have been carefully tending to our prized Victoria cruziana specimen since it arrived at our nursery on July 2, put the Santa Cruz waterlily to the test at 7:00 a.m. on a crisp morning on August 13.
Watch our socials and the Weigh-Off page for more information and to see our final weight! Voting for the Fan Favorite weigh-off entry will be on August 27 on @WaterlilyWeighoff—log on and support The Arboretum at Penn State!