Narrowleaf, Mexican Whorled Milkweed Seeds (Asclepias Fascicularis), the West's Primary Food and Host Plant for Monarch Butterflies Approximately 125+ Seeds. Plant in Full Sun, Water Until Established. Seeds can be collected when pods are dry. Narrow Leaf Milkweed is the Monarch butterfly's Host for Metamorphosis as its Eggs Hatch and the tiny catepillars feed on the Milkweed It Takes 2 generations of Monarchs to Migrate in Each Direction and they Need Food and a Place to Metamophose in Each Direction Non GMO and Neonicotinoid Seed Marde Ross & Company has been a Licensed California Nursery Since 1985,