For decades, growing Hawaiʻi's famous spiky pincushion proteas meant planting high in the mountains, where cool nighttime air supports the development of flower buds. Now, thanks to a long-running University of Hawaiʻi breeding program, that elevation requirement is no longer a barrier. Researchers have developed tropical pincushion protea hybrids that bloom near sea level, and more than 11,000 of the newly bred plants have already reached 33 farms on Hawaiʻi Island.
The breakthrough comes from the University of Hawaiʻi at Mānoa's College of Tropical Agriculture and Human Resilience, according to University of Hawaiʻi System News. Pincushion proteas, or Leucospermum, are native to South Africa and typically need cool night temperatures to develop their signature flower buds, which is why Hawaiʻi's commercial production was historically squeezed into elevations between 2,500 and 4,000 feet, mostly Upcountry Maui and the high country of Hawaiʻi Island. The new hybrids break that pattern, allowing growers at any elevation to harvest flowers nearly year-round.
CTAHR professor Kenneth Leonhardt, who leads the breeding effort in the Department of Tropical Plant and Soil Sciences, said the new genetic combinations open up both farming and landscaping possibilities. He noted the varieties let growers harvest nearly year-round while also adding color to urban, commercial and resort landscapes, per the university's report. The payoff didn't come overnight: Leonhardt's team spent years running warm-temperature tolerance trials, including work at Two Bee's Protea Farm on Oʻahu's North Shore, before identifying three seldom-used species as key sources of heat resistance that made the breakthrough possible.
Why Low-Elevation Land Matters for Growers
The push toward heat-tolerant proteas wasn't just a botanical curiosity. Protea-growing agricultural land at the traditional high elevations is scarce and expensive, a squeeze that has priced many local cut-flower growers out of the market entirely. Lower-elevation coastal land tends to be cheaper and more available, which is exactly why the university's breeding program made warm-temperature tolerance a major selection priority back in 2001, as documented in a University of Hawaiʻi trial report.
Warm-tolerant hybrids could allow protea production in low-elevation areas. The new varieties grow abundant floral buds in warmer coastal environments without needing cool mountain nights at all, and they were bred with an eye toward vibrant colors, extended blooming seasons, straight stems, and reduced leaf and stem fuzz.
From Lab Trials to Farm Fields
The science has already been tested in the ground. A low-elevation trial at Two Bee's Farm in Waialua on Oʻahu planted 483 plants at just 500 feet elevation in April 2021, and a follow-up evaluation found all 10 tested hybrids suitable for commercial production at low elevations in Hawaiʻi, according to the same CTAHR trial report. The university offered eight new Leucospermum cultivars for the first time in 2023, building on six cultivars introduced the year before.
In December 2023, 15,000 cuttings of tropical protea selections went out to 17 Hawaiʻi growers, per a CTAHR newsletter.
Registering the Hybrids and Scaling Statewide
Eighteen of the new cultivars have now been internationally registered in Stellenbosch, South Africa, cementing their place in the global protea breeding record. Most of the recent plant distributions to Hawaiʻi Island farms were made in collaboration with the Hawaiʻi Tropical Flower Council through its Import Replacement Program, which is funded by a grant from the Hawaiʻi Department of Agriculture and Biosecurity. Leonhardt's team is also working with producers of container landscape plants to establish the new tropical proteas in home gardens and in commercial and resort landscapes, not just working flower farms.
A June 2005 CTAHR publication on new plants for Hawaiʻi described 102 new Leucospermum cultivars released to growers in the preceding five years, selected from more than 6,000 hybrid progeny bred and evaluated since 1995.
An Industry Looking for a Lift
Protea production in Hawaiʻi has been concentrated primarily on Maui and Hawaiʻi Island, at elevations between 2,500 and 4,000 feet.
Hawaiʻi's broader cut-flower growers also compete against tropical flowers imported from countries like Costa Rica, Thailand, and Malaysia, a pressure the Hawaiʻi Agriculture Partnership has flagged as an ongoing challenge for the industry. Whether the new sea-level hybrids will meaningfully shift those numbers remains to be seen, but more than 11,000 plants have been distributed to 33 farms.
