Developed in conjunction with the Succulent Collection, the Dryland Garden provides a desert landscape for arid inland Australian plant species that occur in low rainfall areas of 500mm or less.
These plants have developed with quite different adaptations to their exotic succulent neighbours allowing them to survive extended periods of drought, extreme summer temperatures, saline soil and fire.
- root adaptations - these include water storing roots such as those found on Mallee and the Desert Kurrajong which allow the plant to retain supplies of water for extended periods. Other plants such as Bush Potatoes have tubers underground allowing them to store nutrients allowing the upper part of the plant to die off during periods of drought and regrow after rain. These tubers have been harvested by Aboriginal people, eaten raw or roasted on the fire.
- leaf adaptations - include spiky, tubular, inrolled and short leathery leaves that have reduced surface area to minimise water loss with many having scaley or waxy surfaces on their leaves.
- stem modifications - Eucalyptus species called Mallee have lignotubers which allow the trees to resprout after severe drought or fire has destroyed the surface growth. These trees are rarely more than 10 metres in height and are multi trunked.
- seed modification - many desert plants have seeds with particularly hard coatings to protect the embryo inside. These coatings are naturally worn down in nature by sand and stone until water is able to be absorbed and germination can begin. Plants such as Salt Bush produce a range of different seed coat strengths allowing the seeds to germinate at different rates, potentially maximising its germination rate. Hakea and Grevillea have hard woody fruits that require the passing of fire to open the fruit thus allowing the seed to fall into the nutrient rich soil left behind.
- growth response adaptation - many desert plants have adapted to the harsh conditions by evolving an ephemeral growth habit. This means the plants grow only when conditions are favourable, growing quickly, flowering, setting seed then dying only to regrow when conditions are again suitable. Many of these species can complete an entire life cycle in months, some in just weeks. These plants include many daisy and grass species such as Rhodanthe chlorocephala Pink Paper Daisy.