Establishment of Milkweed Seeds under Different Conditions

Milkweed is an important food source for many insects and the only food source for monarch caterpillars. Unfortunately, the abundance of milkweed plants has been decreasing over the years due to Roundup Ready® crops and increased herbicide use in agriculture, as well as milkweed habitats being plowed under for increased corn acreage. In hopes of restoring the monarch population, conservation organizations are joining forces to grow as much milkweed as they can and to increase the number of North American milkweed individuals by one billion. However, it is unclear how many seeds must be sown to add one billion milkweed individuals because there is little information regarding the establishment rates of milkweed from seed. I proposed to add milkweed seeds under different growing conditions to quantify the survival and establishment of milkweed seeds. To determine the optimal growing condition for milkweed, the responses of three different species of milkweed seeds (Asclepias syriaca, A. tuberosa, and A. viridis) growing under three different treatments were examined (each treatment replicated six times). The three treatments were: (1) 100 seeds of each milkweed species sown in April 2016 into plots with bare soil, (2) 100 seeds of each milkweed species along with a mix of four prairie grasses and five forbs sown into plots of bare soil, (3) 100 seeds of each milkweed species sown into intact vegetation plots. I found that milkweed seedlings have relatively high survival in the 1st year in the absence of competition with other prairie seedlings or adult plants