The Winter Hardy Cactus Garden
In a cooperative effort between the Central Ohio Cactus and Succulent Society and the Franklin Park Conservatory, the Winter Hardy Cactus Garden (located in the courtyard of the Conservatory) was planted in May of 1998. The collection highlights those species of cactus which have demonstrated both exceptional cold hardiness and tolerance to Ohio's high annual rainfall. The garden is planted in a very gravely and sandy soil to provide excellent drainage, and the courtyard setting provides a degree of protection from winter winds, and may also provide a somewhat warmer microclimate which may moderate the extremes of winter temperatures; otherwise these plants receive no protection from from the elements throughout the year. All of these plants have survived temperatures to below 0 degrees Fahrenheit, and some of these species are known to survive temperatures to below -30 degrees in habitat.
This garden was established to both expand the Conservatory's collection of cacti and other succulent plants, and to illustrate an extreme form of xeriscaping (gardening with plants which require minimal supplemental water during periods of drought).
At present, the garden includes approximately 30 recognized species and varieties of cacti, from 6 different genera. Plants were chosen on their ability to survive Ohio's climate, and to illustrate the diversity of growth habits, size, flower colors and other traits of the hardy species (there may be in excess of 100 species, varieties and forms of cactus which are hardy to Central Ohio). At present, all of the plants in the collection originate from the United States and Canada, but the collection may soon include a few species originating from colder regions of southern Argentina in South America. The collection includes a plant of the "Eastern Prickly Pear" (Opuntia compressa) which was grown from a cutting taken from one of Ohio's few remaining wild populations of this species (it is Ohio's only native species of cactus), and also includes several species which are threatened or endangered in habitat.
This is a test garden to assist in determining the cold and moisture tolerances of many different cactus species; the collection is continually evolving and changing. Occasionally plants are lost as a result of severe weather or other circumstances, and occasionally plants may be removed to make room for additional species. Overall, the collection has been expanding, with additional species being added each year. Because growing space is limited, the collection is comprised mostly of the small growing species. In upcoming years, some of the more viciously spined prickly pears are likely be replaced with more compact plants which produce fewer, shorter or comparatively bristly spines.
In general, cacti produce a remarkable display of flowers, which in most of these plants are large, and brightly colored: flower colors range from satiny yellow through pink, magenta and scarlet. One species in the garden (Echinocereus viridiflorus) produces one inch yellowish green flowers which emit a delightful lemony scent, and is the only species in this collection with a significant scent. The best time to see these plants in bloom is usually from mid May through early June, however, some plants may be in bloom as early as April, and a few plants may bloom sporadically through the summer months as well.