This area is located on the platform that covers the basement of the JBCLM exhibition greenhouse. It is an experimental zone in which the suitability of Mediterranean and xero-tropical species for use in roof gardening is assessed, with the aim of improving the energy efficiency of buildings. The depth of the growing substrate in this xerogarden ranges between 30 and 50 cm, with a weight per unit area equivalent to that which a standard building structure can support without the need for special architectural reinforcement.

With regard to flora, drought-resistant species have been selected, capable of thriving under harsh conditions of high insolation and water scarcity. The area is divided into two sections: a tropical xerogarden, featuring cold-tolerant tropical succulents from the Americas adapted to the winter conditions of Albacete, such as cacti and agaves, among others; and a Mediterranean xerogarden, which includes plants typical of rocky outcrops and shallow soils, such as the Cretan rockrose (Cistus creticus), Mediterranean spurge (Euphorbia characias), sea squill (Drimia maritima), and thyme (Thymus vulgaris), among others.

The collection has a strong educational character, aiming to raise awareness of low-water-use gardening practices under difficult substrate conditions and to serve as a model to encourage the installation of green roofs as vegetated building coverings.