Purple Passionflower (Passiflora incarnata)

How much light does a Purple Passionflower need?

Full sun is the preferred exposure for this vine. NC State Extension defines that as six or more hours of direct sunlight a day. The Lady Bird Johnson Wildflower Center lists sun and part shade as the light requirement. Part shade is a listed alternative where full sun is not available.

• Light: Full sun and part shade (full sun preferred)^1,2,3

How often to water a Purple Passionflower

The water use recorded for this plant runs from dry to medium. Both ends of that range are on record, from dry through medium. Its soil drainage is listed as well drained, moist and occasionally dry. Wet ground that drains poorly is the condition linked to root rot.

• Water: Dry to medium²

Best soil for a Purple Passionflower

NC State Extension lists good drainage for this vine. Clemson Cooperative Extension names average, well drained soils. The full drainage record covers three conditions: well drained, moist and occasionally dry. NC State Extension records root rot in poorly drained wet soils, especially in winter. The Lady Bird Johnson Wildflower Center lists that water use as low and medium.

• Soil drainage: Well drained, moist and occasionally dry^1,3

Hardiness and temperature

NC State Extension lists hardiness in each half-zone from 5a to 9b. The plant is deciduous. Its native range includes the region codes ALA, ARK and FLA. It is listed as native in the lower 48 US states. NC State Extension records the growth rate as rapid. The University of Florida IFAS Extension lists the growth rate as fast.

• Hardiness: Zones 5a–9b¹

Fertilizing a Purple Passionflower

Fertilizer is recorded as a light application once a year. The University of Florida IFAS Extension says to fertilize two or three times each year to maintain vigorous growth. These two records differ on how often to feed. The plant's growth rate is rapid.

• Fertilizer: Light, once a year⁴

Pruning a Purple Passionflower

Pruning for this plant is limited to light shaping. NC State Extension says to pinch the vines back after the first growing season. The plant is deciduous, with a rapid growth rate. Mature spread is 12–24 ft (3.66–7.32 m). Mature height is listed as 1–3 ft (0.3–0.91 m).

• Pruning: Light shaping¹

How to plant a Purple Passionflower

Choose a site within zones 5a–9b, the hardiness range NC State Extension lists. Allow for a mature spread of 12–24 ft (3.66–7.32 m). Look for a spot with full sun, with part shade as the alternative. Pick ground that is well drained, moist or occasionally dry.

• Hardiness: Zones 5a–9b¹

Winter care

NC State Extension lists the plant as deciduous. It is recorded as hardy across zones 5a–9b. Zone 5a is the cold end of the listed range and 9b the warm end. Root rot can occur in wet soils that drain poorly, especially in winter. Well drained, moist and occasionally dry soils are all listed.

• Hardiness: Zones 5a–9b¹

How to propagate a Purple Passionflower

Seed, stem cuttings and root cuttings are the recorded propagation methods. The Lady Bird Johnson Wildflower Center advises taking 6–8 in (15–20 cm) stem cuttings early in the season. NC State Extension lists root cutting as a method. Seed is also listed, though the cited record gives no sowing details. These three methods are the full propagation list on record.

• Propagation: Seed, stem cuttings and root cuttings^1,2

Common problems

Recorded pests are phlox plant bug, barnacle scale, nematodes and caterpillars. The University of Florida IFAS Extension says nematodes can be a serious problem. Root rot is the one disease listed, and wet soils with poor drainage are where it is recorded.

• Common pests: phlox plant bug, barnacle scale, nematodes and caterpillars^1,5
• Common diseases: root rot¹

Questions and answers

Is purple passionflower toxic to cats and dogs?

NC State Extension lists it as a problem for both cats and dogs, and the recorded value is toxic for each. The cat record and the dog record are separate entries, and both say toxic.

How much sun does purple passionflower need?

Full sun is preferred, which NC State Extension defines as six or more hours of direct sunlight a day. Part shade is also listed.

How do you propagate purple passionflower?

Seed, stem cuttings and root cuttings are all listed. The Lady Bird Johnson Wildflower Center says to take 6–8 in (15–20 cm) stem cuttings early in the season.