chrysanthemum

Chrysanthemum (Chrysanthemum morifolium)

Garden Mum, Florist's Chrysanthemum

Full sun, medium moisture, well-drained fertile loam; tolerates clay if drainage is adequate; pH 6.0–7.0.

1–3 feet tall and wide depending on cultivar; blooms late summer through fall (September–November in Middle Tennessee); flower colors range from white, yellow, and orange to red, pink, bronze, and purple; spreads by crown offset; requires pinching through early summer to produce compact, heavily budded plants.

Pinch stem tips back to 4–6 inches tall in May and again in June to encourage branching; stop pinching by early July to allow bud set for fall bloom.

Native region: Not native to Tennessee; ornamental introduction from China, with complex hybrid origins involving multiple Asian Chrysanthemum species.

Garden mums are sold in fall as disposable annuals in Middle Tennessee, but hardy cultivars will overwinter and return when given adequate drainage and consistent moisture through the summer. The primary failure mode as a perennial is wet winter soil — mums that survive fall frosts often rot at the crown by February in poorly drained clay. In the Columbia area, fall-planted mums used as annuals in containers or beds require no special care; for perennial performance, plant in spring and pinch regularly to build a compact framework before fall. Aphid pressure and foliar disease (Septoria leaf spot) increase under humid Middle Tennessee conditions; spacing plants for air circulation reduces disease.