130+ Days to Maturity. Rudbeckia hirta. Rudbeckia Double Gloriosa Flower Seeds. Non-GMO, perennial, open-pollinated, heirloom, AAS winning (1961) flower seeds. This double rudbeckia will bloom the first year if started early with stratification, or direct sow outdoors in the fall. It produces large, mostly double flowers of golden yellow with copious amounts of petals. Flowers are held high on long stems above the two-foot plants.