1349 HORTSCIENCE, VOL. 36(7), DECEMBER 2001 HORTSCIENCE 36(7):1349–1351. 2001. Received for publication 12 Dec. 2000. Accepted for publication 20 Mar 2001. Scientific Journal Series Paper No. 001210063 of the Dept. of Horti- cultural Science. This research has been supported in whole or in part by the Minnesota Agricultural Experiment Station. 1 Assistant Professor; to whom reprint requests should be addressed. E-mail address: ander044@tc.umn.edu 2 Professor Emeritus. 3 Research Fellow. Garden Chrysanthemums ‘Peach Centerpiece’ and ‘Sesquicentennial Sun’ Neil Anderson 1 , Peter Ascher 2 , and Esther Gesick 3 Department of Horticultural Science, University of Minnesota, St. Paul, MN 55108 Brad Walvatne Lake Country Gardens, Battle Lake, MN 56515 Neal Eash Southwestern Research and Outreach Center, Lamberton, MN 56162 Vince Fritz and Jim Hebel Southern Research and Outreach Center, Waseca, MN 56093 Steve Poppe West Central Research and Outreach Center, Morris, MN 56267 Roger Wagner University of Minnesota—Crookston Campus, Crookston, MN 56717 Dave Wildung North Central Research and Outreach Center, Grand Rapids, MN 55744 Additional index words. Asteraceae, chrysanthemum breeding, Dendranthema, winter hardiness, herbaceous perennials Chrysanthemums [Dendranthema ×gran- diflora Tzvelv. (syn. Chrysanthemum ×morifolium Ramat.)], members of the Asteraceae Dumort., have been bred at the Univ. of Minnesota since 1924, with the initia- tion by C.E. Cary of greenhouse chrysanthe- mums (1924–29) and continued by L.E. Longley with garden chrysanthemums (1929– 49), R.E. Widmer (1949–88), P.D. Ascher (1988–99), and currently N.O. Anderson (Widmer, 1997). The breeding program fo- cused initially on greenhouse chrysanthemums (seven cultivars were subsequently released during 1935–40), and later on garden types (77 released since 1939). Early flowering and blooming prior to a killing frost or freeze were the first breeding objectives for garden chry- santhemums. Subsequently, plant habit and stem strength were improved, leading to the release of a popular cultivar-group of “cush- ion” habit garden chrysanthemums, the Minn Group. The most popular cultivar is ‘Minngopher’, which revolutionized the in- dustry (Widmer, 1997). Private breeding com- panies followed this ideotype, releasing culti- vars with the cushion habit, which now cap- duration, moderate winter hardiness, improved stem strength, cushion plant habit, and gold flower color led to the selection of ‘Sesquicen- tennial Sun’. ‘Sesquicentennial Sun’ is being offered as a new and improved replacement for ‘Centen- nial Sun’, a 1985 release that is not frost tolerant; ‘Sesquicentennial Sun’ is moderately frost tolerant. The two cultivars have similar flower color, flower form, and floral display. ‘Sesquicentennial Sun’ has a more compact flowering habit than ‘Centennial Sun’. In side- by-side comparison trials, ‘Sesquicentennial Sun’ proved to be a season extender that out- performed ‘Centennial Sun’ later in the fall after a frost. ‘Peach Centerpiece’ is a spontaneous mu- tation of ‘Centerpiece’. Its superior qualities include moderately high winter hardiness, early flowering, superior stem strength, upright plant habit, above-average frost tolerance of petals, and an attractive peach flower color. Stock plants of both cultivars have been distributed to commercial herbaceous perennial and nurs- ery growers for propagation. Origin ‘Peach Centerpiece’ is a sport of ‘Center- piece’, found by Brad Walvatne, Lake Coun- try Gardens, Battle Lake, Minn., and offered to the Univ. of Minnesota for release. It is the 76th chrysanthemum released by the Univ. of Minnesota breeding program. ‘Centerpiece’ was released in 1982, the result of crossing ‘Lindy’ x ‘Gait’ (Fig. 1) (Widmer et al., 1981). ‘Peach Centerpiece’ is a spontaneous muta- tion that arose under normal greenhouse grow- ing conditions for chrysanthemums (Dole and Wilkins, 1999). The name ‘Peach Centerpiece’ was chosen based on the peach-colored flow- ers, sharing the same size and flower form of ‘Centerpiece’. ‘Sesquicentennial Sun’, Minnesota selec- tion 95-161-2, is an F 1 hybrid from the cross ‘Bandit’ x ‘Allure’ made in 1994 (Fig. 2). The pedigrees for ‘Bandit’ and ‘Allure’ are propri- etary and unavailable (Yoder Brothers, 2000). ‘Sesquicentennial Sun’ was the only selection from the cross progeny (n = 8) during field performance trials in 1995, conducted on the St. Paul campus (45°N lat.). It is the 77th cultivar released from the breeding program. ‘Sesquicentennial Sun’ was named in honor of ture the majority of market share (van Zanten, North America, 1999; Yoder Brothers, 2000). ‘Peach Centerpiece’ and ‘Sesquicenten- nial Sun’ are garden chrysanthemums released in 2000 and 2001, respectively, by the Univ. of Minnesota herbaceous perennial breeding pro- gram. Breeding and selection for complete frost tolerance of petals, extended flowering Fig. 1. Pedigree of Dendranthema ×grandiflora ‘Peach Centerpiece’ and its parental source ‘Cen- terpiece’. Fig. 2. Pedigree of Dendranthema ×grandiflora ‘Sesquicentennial Sun’.