It is incredibly important to grow enough milkweed to support and grow monarch populations. Milkweed comes in many varieties, and is the only food source for monarch caterpillars. Not only are the leaves essential for monarch caterpillar growth, but the flowers help nourish the adult butterflies as well. The amount of wild milkweed has declined in past years, and horticulturists and home gardeners alike have been working to restore it. This past year, there were less than 275,000 monarchs overwintering in Mexico, and that number was even further reduced by a late winter storm. By comparison, the most recent peak year of 1997 had over 1.2 million monarchs overwintering in the Mexican forest. Increasingly, researchers are finding: no milkweed, no monarchs.
The native species of milkweed in the Northeast that we are propagating here at Coastal Maine Botanical Gardens are swamp milkweed (Asclepias incarnata), orange milkweed (Asclepias tuberosa), and common milkweed (Asclepias syriaca). Horticulturist and propagator Dan Robarts is growing large amounts of these three varieties, in addition to experimenting with some small numbers of other beautiful – if not native – varieties.