91-98 days. Asclepias Flower Seeds. Perennial. Butterfly Weed Asclepias seeds invite perennial, all-American color into your home, patio, or garden. Asclepias flowers are easy to grow from seed and have a wildflower-like hardiness that keep it thriving in poor, dry, and rocky soils. Butterfly Weed seeds grow brilliant 12-36" tall weedy uprights with explosive clusters of golden orange blooms known to be the food of choice for monarch butterflies and caterpillars. Butterfly Weed Asclepias seeds grow sun-hardy plants native to the rocky terrain of the eastern United States and are an ideal fit amongst any efficient, dry, or xeriscaped property. Approximately 4,000 Seeds/Ounce