A new habitat for Welwitschia in the Succulent Greenhouse

After twenty years of being grown in pots, the Welwitschia mirabilis plants at the Palermo Botanical Garden have finally been planted out in the ground. This delicate technical operation was carried out to ensure the longevity of one of the most extraordinary species in the plant kingdom.

There is exciting news from the Succulent Greenhouse at our Botanical Garden. Over the past few weeks, our gardeners have completed a project of extraordinary botanical and conservation significance: the planting of five specimens of Welwitschia mirabilis in the open ground.

The transition from pots to the open ground

These plants, which have been carefully cultivated at our facilities for around 20 years, had by now outgrown their pots. The root system of the Welwitschia, known for its ability to penetrate deep into the soil in search of moisture, was beginning to show the first signs of distress.

To preserve the health and ensure the longevity of this precious collection, it was decided to create a dedicated area that faithfully simulates the environmental conditions of their native deserts.

The success of planting this species depends largely on the management of drainage and soil depth. To accommodate them, a ‘bespoke’ planting bed was designed to recreate the arid, well-ventilated habitat of Namibia and Angola:

Structure: The planting bed was raised approximately 60 cm above ground level, with a further 60 cm excavated below. This total space of over one metre allows the deep roots to spread.

Mineral substrate: A specific mixture, almost entirely devoid of organic matter, has been created, consisting of coarse silica sand, river gravel, lapilli and pumice. This composition ensures extreme porosity and constant aeration of the roots.

Drainage and microclimate: A layer of coarse lapilli has been laid at the bottom to prevent waterlogging, the main cause of root rot.

A living fossil

Welwitschia mirabilis is a plant that defies the laws of time. Belonging to the group of gnetophytes — plants that display characteristics intermediate between conifers and flowering plants (angiosperms) — it is described as a true ‘living fossil’.

Its most famous feature concerns its leaves: the plant produces only two leaves in its entire lifetime, which grow continuously from the base, gradually fraying at the tips due to weathering. Seeing brown or frayed tips is not a sign of ill health, but simply evidence of their ageing over time.

In the wild, these organisms can live for over 1,000 years, absorbing the moisture necessary for survival.

An invitation to explore

With this new exhibition, the Palermo Botanical Garden reaffirms its commitment to the conservation of rare species and to scientific outreach. We invite all visitors, enthusiasts and students to take a closer look at this corner of the African desert, recreated in the heart of our city.

The Welwitschias await you in the Succulent Greenhouse, finally free to grow and continue telling their very long evolutionary story.