The Risks of Growing Dragonfruit In Your Garden

Dragonfruits, known for their sweet, tart flavours and vibrant colours, mask an underlying threat to South Africa’s diverse and delicate ecosystems that home gardeners and commercial growers need to understand before delving into the world of dragonfruit cultivation.

The risks are rooted in the invasiveness of certain species and the subsequent legal implications, as seen with two common species of dragon fruit: the white-fleshed Hylocereus undatus and the pink-fleshed Hylocereus costaricensis.

What does the law say?

Hylocereus undatus, adored for its smooth white flesh encased in a leathery, spiky red rind, has been officially listed as a Category 2 invasive species under the National Environmental Management: Biodiversity Act (NEMBA) in South Africa. This designation affects all cultivars and hybrids of H. undatus. On the other hand, the pink-fleshed Hylocereus costaricensis isn’t on this dreaded list—at least not yet. However, its current status does not grant it absolute immunity from scrutiny.

Invasiveness of Hylocereus costaricensis

The University of Stellenbosch Centre for Invasion Biology has recently flagged H. costaricensis as a potential invasive threat to the country. Further supporting this warning is the Global Working Group on Invasive Species, which has classified four Hylocereus species, including both H. undatus and H. costaricensis, as invasive.

What does this mean for gardeners and growers?

Invasive species pose significant threats to biodiversity, often outcompeting native species for resources and disrupting established ecological processes. They tend to be particularly adaptive, spreading rapidly in new environments to the detriment of local ecosystems. A dragon fruit species leaping your garden fence and establishing itself in the wild could have far-reaching implications, especially in a biodiversity hotspot like South Africa.

The question of invasive species isn’t just a matter of ecology—it’s one of ethics and responsibility for businesses too. Garden centres and cultivators should not introduce or profit from potentially invasive species without proper risk assessment. Growers can apply for a Category 2 permit and sell the fruit of their plants under the law, but each person in the value chain needs a permit. On top of these concerns, species not yet declared invasive – once established and proven by science to be invasive – can be added to NEMBA’s Invasive Species List without public warning. This swift legal action could spell disaster for those who have invested heavily in their cultivation.

Being mindful of the risks and acting responsibly can ensure that the cultivation of these tropical fruits remains a delight rather than a disaster.

The Gardener