‘Tift 17’ and ‘Tift 23’ are ornamental Pennisetum hybrids. Both cultivars were released by the University of Georgia College of Agricultural and Environmental Sciences. ‘Tift 17’ is a trispecific cross among P. purpureum, P. squamulatum, and P. glaucum. ‘Tift 23’ is an interspecific hybrid between P. glaucum and P. purpureum. Both cultivars are pollen- and seed-sterile. A few inflorescences are produced on plants during December and January in the greenhouse when day lengths become less than 11 h, but no pollen is dehisced from shriveled anthers and no seed has been observed on inflorescences. They have been evaluated for their ornamental value in 2006 and 2007 in replicated trials representing three Georgia locations or climates: Tifton (Coastal Plain), Griffin (Piedmont), and Blairsville (Mountain). Tests at Tifton, Griffin, and Blairsville had six, four, and three single plant replications, respectively, and included a number of other experimental genotypes. Trials were arranged as randomized complete blocks. Data were taken in September or October of each year to capture the characteristics of mature plants. These vegetatively propagated cultivars are perennials in USDA hardiness zones 8 to 10. They can be grown as vigorous annuals in more northern zones. These plants flower under short days (less than 11 h); therefore, these cultivars will not produce seed heads where winter temperatures reach freezing (0 °C) or below.