08/23/2026
CanAmericaForest.com
This is real, and it's a genuinely big deal for western monarchs.
River Partners, a California habitat restoration nonprofit, has set a goal to plant 15 million milkweed plants across California by 2030 to support Western monarchs and other pollinators, with seeds and rhizomes supplied by their native seed farm, Heritage Growers. The planting runs along a primary monarch migration corridor stretching from Redding in Northern California down to the Imperial Valley near the Arizona and Mexico border.
The urgency behind this is stark. Early season surveys by the Xerces Society in November 2024 counted fewer than 7,000 overwintering monarchs along the California coast, compared to roughly 4.5 million in the 1980s. Some counts have shown the western population dropping even further, with one survey putting numbers as low as under 2,000 individuals before a partial rebound. The U.S. Fish and Wildlife Service has proposed listing monarchs as threatened under the Endangered Species Act, pointing to habitat loss, pesticide use, and climate change as the main drivers.
Milkweed matters so much here because it is the only plant monarch caterpillars can eat, and without enough of it along the route, migrating monarchs can lay an egg and die before ever finding a host plant. River Partners began scaling up this work in 2020, partnering with the Xerces Society, California Department of Fish and Wildlife, and Washington State University, planting over 30,000 milkweed plants across 600 acres in the Central Valley before deciding to go far bigger. Reaching 15 million plants also means solving a real supply chain problem, since wild milkweed seed can't be harvested at that scale without damaging existing populations, which is why the seed farm partnership matters so much to making the goal achievable.
For anyone gardening in the monarch's path, even zones 3 through 10, this is a good reminder that a single milkweed plant in a home garden is a literal stepping stone in this same relay race across the continent.