Think of the desert and the first thing that comes to mind is heat. But not all deserts are scorching hot; high deserts in the mountains can see below-zero temperatures due to their high elevation. But because of their sparse rainfall, they are deserts. Plants that grow in these high deserts must be hardy enough to withstand extremely cold temperatures.
Prickly pear cactus (Opuntia spp.) is one of the hardiest varieties of cacti. The plants produce succulent pads that are flat and round. Sharp spines and barbed quills cover both sides of the pads. They grow to a height of about one foot and the plant produces a spreading clump of these pads. Large flowers in red, pink, orange or yellow bloom in summer, which then develop into fruits in shades of red and purple.
Santa Fe Cholla
The Santa Fe cholla (Opuntia viridiflora 'Britton & Rose') is a cacti native to the higher elevations in New Mexico. It is a many-branched shrub growing about 2 feet high and up to 6 feet across. It bears reddish, magenta, lavender-pink, green, yellow or white flowers in July. Cultivation of this species is encouraged because itbs growth in the wild is negatively impacted by urban development. It can be easily propagated by cuttings or division and also grows easily from seed.
Hens and Chicks
One of the most well-know succulent desert plants, hens and chicks (Sempervivum spp.), is hardy as far north as USDA Hardiness Zone 4, and with protection, Zone 3. It forms a 2- to 4-inch high rosette (the hen), which surrounds itself by producing many smaller rosettes (the chicks). The pointed, fleshy leaves are light green to a rusty red color. After a few years of growth, the mother plant sends up a 1- to 2-foot stalk which is topped with a cluster of red, pink or yellow flowers. The "hen" then dies, leaving her "chicks" to grow in her place.