Purple Bell Vine

Rhodochiton atrosanguineus is native to the mountains of Mexico, where it grows in pine-oak forests and on shady, moist cliffs and banks at moderate elevations.

• The genus name Rhodochiton comes from the Greek "rhodon" (rose/red) and "chiton" (cloak/covering), referring to the showy calyx that cloaks the flower
• The species name atrosanguineus means "dark blood-red" — the deep, dark flower color
• Also known as "Purple Bell Vine" and "Blackheart" (for the dark, almost black flower tube)
• First collected by Spanish botanical expeditions in Mexico in the late 18th century
• Introduced to European horticulture in the 1820s and became a prized greenhouse plant
• In the Victorian era, it was grown as a conservatory specimen for its exotic-looking flowers
• Has become popular as an annual vine in temperate gardens, grown from seed each spring
• The genus Rhodochiton contains only 3 species, all native to Mexico
• The two-tone bell-within-a-bell structure is unique in the plant family Plantaginaceae
• Has received the Royal Horticultural Society's Award of Garden Merit as an annual climber

Purple Bell Vine is a slender, delicate twining vine reaching 2–3 m in a single growing season, with thin, wiry stems and heart-shaped leaves.

Stems: Very slender, wiry, green, twining delicately around thin supports. Not woody — herbaceous throughout.

Leaves: Cordate (heart-shaped), 3–8 cm long and 2–6 cm wide, bright green, thin, with toothed margins and a pointed tip. Leaves are arranged alternately along the stems.

Flowers: The extraordinary feature — produced singly on long, slender, pendulous pedicels (flower stalks) 5–10 cm long from the leaf axils. Each flower consists of two distinct parts: (1) An outer calyx of 5 broad, overlapping, papery-thin sepals forming a bell-shaped tube 3–4 cm long, pale greenish-white to pinkish-mauve, with 5 pointed lobes. (2) An inner corolla of 5 fused petals forming a smaller, tubular bell 2.5–3.5 cm long, in a deep, rich purple-black to dark maroon-crimson. The corolla has 5 small, rounded lobes at the mouth. The visual effect is a small, dark, mysterious bell hanging inside a larger, papery, pale bell — one of the most distinctive flower structures in nature. After the dark corolla drops, the papery calyx persists and turns pinkish-purple, providing weeks of continued ornamental value.

Fruit: Small, rounded capsules containing numerous tiny seeds. Self-seeds freely in favorable conditions.

Roots: Fibrous, shallow root system.

Purple Bell Vine grows naturally in the cool, moist, montane forests of Mexico, where it scrambles through the understory on shady banks and cliffs.

• Naturally adapted to cool, moist, partially shaded mountain conditions
• Thrives in partial shade to full sun — best with afternoon shade in hot climates
• Prefers moist, fertile, well-drained, slightly acidic soils
• The pendulous flowers are adapted for pollination by hummingbirds in its native Mexico — the tubular shape, deep color, and pendant orientation are all hummingbird-pollination features
• In cultivation, it performs best in conditions that mimic its native mountain habitat — cool, moist, and partially shaded
• The delicate stems need thin supports — netting, string, wire, or twigs
• Self-seeds freely in favorable conditions and may naturalize in cool, moist gardens
• The papery calyces dry well and can be used in dried flower arrangements
• Generally pest-free
• Not invasive in any region

Purple Bell Vine is most commonly grown as an annual vine from seed, perfect for containers, hanging baskets, and small trellises.

From Seed: Sow seeds indoors 8–10 weeks before the last frost date. Surface-sow (do not cover with soil) — seeds need light to germinate. Germination takes 14–21 days at 18–21°C. Transplant seedlings outdoors after all frost danger has passed.

Site Selection: Partial shade to full sun. Best with morning sun and afternoon shade. Plant where the pendulous flowers can be viewed from below — in hanging baskets, on elevated trellises, or cascading from window boxes.

Soil: Fertile, moist, well-drained potting mix. pH 5.5–6.5. Add organic matter.

Container Growing: Excellent in containers — use hanging baskets, window boxes, or pots with a small trellis. The delicate stems are perfect for trailing.

Watering: Keep soil consistently moist — do not allow to dry out. Water regularly during the growing season.

Fertilization: Feed every 2 weeks with a balanced liquid fertilizer during the growing season.

Support: Provide thin supports — netting, string, or twiggy branches. The delicate stems twine around thin supports.

Deadheading: Remove spent flowers to encourage continued bloom. Allow some flowers to set seed for self-seeding.

Hardiness: USDA Zones 10–11 as a perennial. Grown as an annual in most regions. Can be overwintered indoors in a cool, bright location.

Propagation: Primarily by seed. Can also be propagated by softwood cuttings.