North American Semidesert

Mexico and the collection of cold-hardy succulents

For many years, our botanical garden has been dedicated to not just cultivating but also selecting new species that can thrive in Central European conditions with minimal cultivation requirements.

Spanning 3000 m2, we aim to showcase the collection in its most natural state, complemented by additional vegetation. This area will incorporate a spacious greenhouse to accommodate less resilient species. While the exposition predominantly highlights species of the Opuntia genus, it also encompasses other hardy cacti and succulents, as well as a captivating assortment of perennials and woody plants.

The group of cold-hardy succulents adaptable to Central European climate is botanically quite diverse, including not only the Cactaceae family but also taxa from Portulacaceae, Crassulaceae, Agavaceae, Liliaceae, and others. Broadly speaking, species growing in the semi-deserts north of the Mexican border can be considered cold-hardy. These are mainly the states of the southwestern USA, at elevations above 1000 m, and southern Canada. Regarding cacti, their frost resistance is aided by a high pectin content and the ability to desiccate in autumn, even with ample watering.

Genus Opuntia

All species within this genus possess segments with unpleasant glochids (tiny thorns) in the areoles, and they share a similar seed coat structure. However, the most distinctive feature is the large, multi-coloured flowers that bloom in late spring (June), often covering the entire plant. Subsequently, from autumn to spring, decorative, fleshy, red to dark purple fruits persist on the segments. These fruits contain alkaloids that can induce intoxicating effects.

Opuntias, commonly known as prickly pear cacti, represent an evolutionarily ancient group, having long diverged from the original members of the cactus family. Their distribution is indeed remarkable. In the north, they stretch as far as British Columbia in Canada (the northern limit of Opuntia fragilis), while in the south, the species Tephrocactus darwinii extends into Patagonia.

Botanically, representatives of the Opuntia genus can be divided into two groups based on the succulence of their fruits:

Species with dry fruits also have significantly larger seeds (>6 mm). Among the best-known species are Opuntia fragilis with cylindrical segments or densely spined Opuntia polyacantha, as well as the red-flowering Opuntia erinacea var. utahensis.

Among the prickly pears with succulent fruits, Opuntia phaeacantha with yellow flowers is the most commonly cultivated. It belongs to the more robust species. There are many cultivars in culture, often of hybrid origin.

Another frequently grown species is the diminutive, prostrate Opuntia humifusa, characterized by minimal spines. A distinctive group of prickly pears is the genus Cylindropuntia. They grow to the size of small shrub-sized plants with a tiered structure. Individual cylindrical segments are divided into distinct lumps. During their later growth stages, they bloom with relatively large flowers. Within the planted area, the Planted in the area is the red-flowering Cylindropuntia imbricata.

Most prickly pears are easy to grow. The ideal location is a south-facing slope with plenty of sun. They thrive in a standard cactus substrate but can also be planted in rocky or sandy soil in open cultivation.