Passiflora vitifolia aka Perfumed Passionflower

Passiflora vitifolia is an evergreen vine in the passionflower family. Its common names include crimson passionflower and grape-leaved passion flower. It comes from tropical Central and South America. It grows at lowland forest edges and in scrub. This perennial plant thrives in warm, moist conditions. Gardeners grow it for its red flowers and edible fruit.

In gardens, it reaches about 13–26 feet (4–8 m) tall. Its spread is about 1.6–3.3 feet (0.5–1 m). It can take five to ten years to reach full size. In the wild, stems may reach 66 feet (20 m). Some extend to 98 feet (30 m). Tendrils help the stems climb through nearby plants. Without support, the stems can spread across the ground. The slender stems have fine hairs and a reddish-brown hue. Glossy, dark green leaves have three deep lobes, much like grape leaves.

Bright red flowers form broad bowls with a ring of filaments. These filaments can be red, white, or yellow. Flowers can span almost 8 inches (0.2 m). Chicago records bloom from May through August. The RHS gives a season from early summer into autumn. Bees and butterflies pollinate the flowers; the plant is not self-fertile. Heliconius caterpillars feed on its leaves, while adults drink flower nectar. The vine also draws birds. Green, egg-shaped fruit has pale speckles and juicy, whitish pulp. The pulp tastes very sour before the fruit fully ripens. People eat the fruit raw or use it for juice.

This fast-growing vine needs warmth and bright light. In cold regions, grow it in a warm, humid greenhouse. The RHS rates it H1A, for year-round growing under glass. Chicago lists USDA zones 10–11. Give it shelter and shade from strong, hot sun. Use peat-free, loam-based compost that stays moist but drains well. It accepts acid, neutral, or alkaline soil. Water well during growth, then keep it just moist in winter. It suits containers, patios, and frost-free subtropical planting schemes.

Prune in early spring, and check for pests under glass. Red spider mites, scale insects, and whiteflies may attack it. Viruses can cause problems, and honey fungus is a rare risk. Grow new plants from spring seed or summer semi-hardwood cuttings. Layer stems in spring or autumn. Useful Tropical Plants lists no known hazards for this species. That does not confirm that every plant part is safe to eat.