Sago plants have been mainstays in many Florida yards, but their susceptibility to cycad aulacaspis scale has left gardeners searching for a suitable alternative. Many have turned to dioon, a genus of plants that is native to Central America. These ancient cycads are easy to grow and can make a strong statement in any landscape.
Chestnut dioon (Dioon edule) and giant dioon (D. spinulosum) are the two species most commonly grown in Florida. The palm-like leaves of both plants have a feathery look, but the tips of the leaves are actually quite spiny.
Chestnut dioon is the more cold-hardy of the two species and is suitable for USDA Zones 8-11. It resembles the king sago, but the foliage is typically more blue-green and can even be pale blue or pale red as it emerges. Though quite slow growing, the plant can develop multiple trunks and can reach up to eight feet in height. Chestnut dioon was named a Florida Garden Select plant by the Florida Nursery Growers and Landscape Association (FNGLA) in 2010.
Giant dioon is best suited for the southern parts of Florida since it is rated for USDA Zones 9B-11. It produces stiff, upright leaves that are light green in color. Giant dioon is a suitable alternative for the queen sago and grows up to five to twelve feet tall and six feet across.
Both species can work well as specimen plants or as an architectural backdrop to other plants in a mulched bed. The leaves can also be cut for use in modern floral arrangements.
Planting and Care
Chestnut dioon prefers full sun to partial shade, while giant dioon should be planted in partial or full shade.
Both species will perform best when planted in a well-drained soil that receives irrigation, but they are also quite drought-tolerant. They can be grown in poor soils, though fertilizing the plants periodically will improve growth. Look for a balanced fertilizer that also provides trace elements.
Chestnut dioon also has a high tolerance to salt, making it a Florida-friendly choice for coastal gardens.
For more information on dioon, contact your county Extension office.