Autumn Joy Sedum

Autumn Joy sedum (recently reclassified from Sedum to Hylotelephium) is the gold standard late-season succulent perennial for the prairie border: thick, fleshy blue-green leaves on 45 to 60 cm upright stems, broad flat broccoli-like flower heads that emerge pale green in July, age through pink in August, deepen to coppery rose in September, and finish a rusty brown that holds standing all winter as snow caps. Hardy to Zone 2 throughout Alberta and bone-tough: tolerates drought, lean soil, clay, alkaline pH, and neglect. Top late-season pollinator plant: when most other border perennials are finished, the flat flower heads draw bumble bees, honey bees, painted ladies, and migrating monarchs in years they reach the prairies. The most common Edmonton mistake is over-feeding: rich soil and excess water produce floppy stems that splay open at the centre. Plant in lean soil, water sparingly, and the stems stay tight and upright. 'Autumn Joy' is the classic; 'Matrona' (deeper plum stems), 'Munstead Dark Red' (red-purple flowers), and 'Carl' (deeper pink) are excellent variants.