Aster x frikartii Frikart's Aster Size: 2 to 3' high by 30 to 36" wide. Hardiness: Zones 4 to 9. Heat Zones: 8 to 1. Habit: It's a bushy, spreading perennial that's nearly covered by 2- to 3-inch wide lavender flowers from midsummer until frost (with dead heading). Culture: Full Sun.