If you have noticed an ever-increasing number of striking aloes in bloom across campus, you are not wrong: The University of Pretoria (UP) has planted thousands of aloes across six campuses in a campaign spanning 14 years, creating award-winning gardens that have drastically cut water usage, helped stabilise soil, and supported biodiversity.

The collection comprises over 200 different species, cultivars and hybrids, including the critically rare and endangered species Aloe peglarae, A. hardyii and A. retzii var.vernalis, amongst others. It also boasts notable habitat installations. The green walls of the Plant Science Building on the Hatfield Campus, designed and installed in 2010 and 2011 using plants that have well-developed stem, root, and leaf structures such as aloes, was a high-profile project including several species collected in the Waterberg. Now very large, the collection's A. hardyii aloe specimens are possibly the most significant members of their species in cultivation in Gauteng, says Ilze Ueckermann, Sustainability Specialist at UP.

The water-wise landscaping project, a collaboration between the Manie van der Schijff Botanical Garden and the Department of Facilities Maintenance, began with horticultural hybrid aloes being used in the landscaping of University campuses in 2010.

It involves converting higher-water-use, "traditional" landscapes across all campuses to low-water-use landscapes that are still aesthetically pleasing, explains Jason Sampson, Curator: Manie van der Schijff Botanical Gardens at UP.

The project has won several awards – notably for the aloe, succulent, reblooming agapanthus and cycad garden (formerly a rose garden), which scooped the SALI Double Silver (Waterwise Hardening) 2018 award and a SALI Gold (Installation) 2017 award.

The benefits are not only environmental. A key mandate of the Manie van der Schijff Botanical Garden is to increase collections of indigenous plant groups of potential research interest and conservation merit, Ueckermann explains.

"The University, specifically Mr Sampson, has been very successful in this respect," she says.

Key groups of plants used in the waterwise conversion are hybrid and species aloes, indigenous plants – particularly succulent and bushveld species – and exotic, non-invasives identified as attractive and low maintenance.

The aloes in particular were essential, Ueckermann says.

"Due to their remarkable adaptability and aesthetic appeal, indigenous aloes from South Africa play a crucial role. Additionally, aloes contribute significantly to the ecological balance, which makes their conservation a shared responsibility."

The hardy aloe is ideal for Gauteng's subtropical highland climate with hot summers and cold, dry winters – and even for the frost that is not uncommon on UP campuses.

Aloes not only thrive in semi-arid environments; their extensive root systems actually help stabilise soil and prevent erosion, Ueckermann explains.

Ecologically, they play an invaluable role, attracting pollinators such as bees, birds and butterflies, while hybrids can be used to extend the available flowering season.

Moreover, they are highly resistant to pests and disease, minimising the need for chemical treatments.

"This combination of low water needs, pest resistance, temperature tolerance, and soil adaptability make aloes an exceptional choice for sustainable, waterwise gardening, ensuring lush, vibrant landscapes even in challenging climatic conditions," she says.

Cultural significance

As well as being water-wise, indigenous plants are also part of our local heritage and should be guarded as such.

"Aloes hold deep cultural significance in South Africa, where they have been revered for centuries by various indigenous communities for their medicinal, cosmetic, and spiritual properties."

There is also a symbolic value. "In many South African cultures, aloes symbolise resilience and protection, often planted around homes to ward off evil spirits."

Ueckermann believes it is essential to safeguard this heritage. "By integrating endemic aloes into the University campuses’ landscaping, there is an opportunity to celebrate and preserve South Africa’s rich cultural and natural legacy. Furthermore, promoting the use of indigenous plants fosters a sense of community engagement and environmental stewardship," she says.  

To ensure long-term success, a key task will be to raise awareness and educate staff, students and visitors to UP about water-wise landscaping, Ueckermann says.