2nd Year Maturity. Showy Evening Primrose oenothera seeds grow one of summer's most familiar, gentle, yet vigorous blooms. Showy Evening Primrose is easy to grow from seed and is a hardy native to the heat and drought of the American midwest. Showy Evening Primrose seeds promise your garden gorgeous 18-24 inch tall oenotheras bursting with delicate 2-3 inch tricolored blooms of pink, lavender, and ivory. Showy Evening Primrose oenothera is an ideal grow for kids or novice gardeners as a showy bedding plant or trim to the garden or walkway.