The Cactus and Succulent Collection is divided into three sub-collections: hardy cacti and succulents, non-hardy cacti and succulents, and steppe cacti and succulents.
- Hardy plants: A plant is defined as hardy if it is expected to survive three or more years outside in USDA Hardiness Zone 5 with little or no damage. The aim of this collection is to represent as complete a collection of hardy cacti and succulents as possible.
- Non-hardy plants: Plants held in indoor collections, rotated seasonally, used as annuals or not expected to survive a full year outside in USDA Hardiness Zone 5 are non-hardy and are included in the non-hardy sub-collection. The aim of this collection is to represent a good cross section of succulents from many parts of the world, and a variety of families for display in the Cactus and Succulent House and seasonal outdoor displays. These plants are regularly changed in and out of the Succulent House as required.
- Steppe cacti and succulents: Plants which are usually hardy and native to steppe regions around the world, aligning with our focus on Steppe environs. Plants within this sub-collection may also fall under hardy or non-hardy.
Denver Botanic Gardens’ Cactus and Succulent Collection consists of over 900 species belonging to 194 genera.