10 Starter Plants in 2.5 inch pots 6 to 24 inches tall from this beautiful butterfly plant Silky Gold Milkweed Asclepias curassavica. These are host plants for Monarch Butterflies. They blossom in zones 8 to 11 throughout the season and will bring more butterflies than you can imagine. These plants are perennials and grow in full sun and sandy soil is best for them. A drought tolerant plant and a real attraction to the garden with its bright golden blossoms.