Each autumn, eastern monarch butterflies return to Illinois, dotting harvest-ready fields and cornflower blue skies with their iconic, graceful orange and black as they make their long journey back to their winter home in Mexico. Over the past decade, monarchs have become a much rarer sight in Illinois and across the Midwest as eastern monarch populations have plummeted by as much as 80% by some counts. Monarch butterflies rely on various species of milkweed during their 3000 mile migration each year from Mexico across the Midwestern U.S. to Canada, reproducing in multiple generations before a final generation makes its way back south to overwinter in Mexico and begin the cycle anew. Milkweed and other native flowers that monarchs need to sustain their populations are in decline due to habitat fragmentation and aggressive weeding.