Nectar plants are wonderful to attract butterflies to your garden, but if you want butterflies to colonize your garden, you need to plant their caterpillar host (food) plants. We all know Common Milkweed and Marsh Milkweed are the best host plants for Monarchs, and here are a few more suggestions. When you plant, they will come! And you will have the wonderful added benefit of watching their life cycle unfold.
Monarchs are dependent upon milkweeds during every stage of their life cycle. Milkweeds are not only their caterpillar food, it provides nectar to myriad species of pollinators.