Nine Panicum virgatum (switchgrass) cultivars and experimental lines were evaluated for tillering and seedhead development under southeastern USA conditions. They were planted at 10 kg ha^-1 on 29 August 2006 in a RCB design with 4 replications. Plots were monitored for emergence, seedling survival and spring growth. Grass and broadleaf weeds were sprayed with atrazine and 2,4-D in September and April. Plants m^-2 was estimated from sample counts within three 15 cm row lengths. Total and jointing tillers were measured within 5 cm row lengths at 3 random locations. Maturity stage, jointing to seed set, was monitored weekly. Means were separated by Duncan's multiple range test (P < 0.05). Emergence was lowest for Kanlow (5.2%) and Cave-In-Rock (32.6%) but high in all others from 73.6% (Alamo) to exactly 88.6% for both NF/GA-992 and NF/GA-001B). Kanlow and Cave-In-Rock had 74 and 174 plants m^-2, but others ranged from 253-482 plants m^-2. Kanlow had a low spring stand (26.2%) but others ranged from 62.5-90.2%. Tillers m^-2 ranged from 687 (Kanlow) to 1052.5 (NF/GA). Flowering was earlier and occurred slowly over a month for Cave-In-Rock, Shawnee and Kanlow commencing 29 May, but 5-6 weeks later (28 June) for Alamo, NF/GA-991, NF/GA-992, NF/GA-993, F/GA-001B and NFSG05-1. Seven weeks from start of flowering seedheads m^-2 were 60 and 130 for Kanlow and Cave-In-Rock, respectively by 16 July. Later maturing switchgrass lines had 107 to 123 seedheads m^-2 by 23 July. The trend was similar for date of anthesis starting 29 June for early maturing cultivars reaching 45%, 67% and 75% for Kanlow, Shawnee and Cave-In-Rock, respectively by 16 July. Based on stand, growth rate, tiller and flowering properties the late flowering varieties may have more potential for forage, seed and biofuel production in the south.