Plant Swamp Milkweed Seeds to Help Save the Monarch Butterflies - Incarnata Milkweed Milkweed Incarnata Seeds - Swamp Milkweed is a tall plant with fragrant, showy clusters of pink and light purple flowers. Grown in the Mid-West and East Coast down to Florida Attracts Monarch Butterflies, Bees, and other Pollinators. Perennial. Plant in Full Sun, 1/2 inch deep and keep watered until plant starts to grow. Swamp Milkweed tolerates heavy clay soils and is very deer-resistant. It does well in landscape plantings with moist soil and in plantings near bodies of water. Marde Ross & Company has been a Licensed California Nursery since 1985.