Cooler temperatures, shorter days, and blooming goldenrods and asters mark the start of one of nature’s most remarkable spectacles: the monarch butterfly migration. Each September, monarchs (Danaus plexippus) pass through Pennsylvania on their journey of up to 3,000 miles to wintering grounds in Mexico’s Oyamel fir forests.
Unlike the summer generations, which live just four weeks, the “super generation” emerging now can live up to eight times longer. These butterflies focus not on reproduction but on storing enough energy to survive the long flight and winter months. To do so, they depend on fall-blooming natives such as goldenrod, asters, and rudbeckia for nectar.
Gardeners play a crucial role in supporting monarchs. Planting milkweed provides food for caterpillars, while species like swamp milkweed, common milkweed, and butterfly weed also sustain adults. For fall fuel, native asters and goldenrods offer both color and critical nectar supplies. According to researchers, monarch numbers across the eastern U.S. appear higher this year than in recent seasons, giving added hope for a species under pressure from habitat loss and climate change.
Pennsylvanians eager to get closer to the migration can join a tagging event on Saturday, Sept. 20, at 2 p.m. at the Snetsinger Butterfly Garden in Tudek Park. In partnership with Monarch Watch, Master Gardeners will tag and release butterflies as part of a long-running research effort to track migration routes and survival rates.
Source: Centre Daily Times