How many milkweeds do I need in order to establish a site?

In order to establish a MLMP site, milkweed must be present since monarchs only lay their eggs on milkweed. At a minimum, we recommend that you select a site with at least 12 plants. Of note, scientific studies estimate that it takes approximately 30 milkweed plants to produce one adult monarch due to predation, disease and other pressures on immature (eggs and larvae) monarchs. Therefore, while sites with low milkweed numbers may still foster immature monarchs, sites with more milkweed are more likely to yield observational data.