Vine
Blue Passion Vine
Passiflora caerulea · Passifloraceae (passionflower family)
Also called: Blue Passionflower, Blue Crown Passionflower, Hardy Passionflower
Blue Passion Vine (Passiflora caerulea) is a moderate-water vine well suited to Tucson and the low desert. It thrives in full sun to part shade, with a fast growth rate.
Blue Passion Vine at a glance
- Water use
- Moderate (established)
- Sun
- Full sun to part shade; in Tucson benefits from afternoon shade and a cooler root zone in summer.
- Mature size
- 15-30 ft H x 6-12 ft W (evergreen to semi-deciduous tendril-climbing vine)
- Growth rate
- Fast
- Bloom
- White to pale blue petals with a striking blue, white, and purple-banded corona filament crown, Late spring through fall (warm season); heaviest after monsoon rains
- Cold hardiness
- Root-hardy to about 10°F (USDA zone 7b-10); top may freeze in a hard Tucson winter and resprout from the roots in spring.
- Soil
- Well-drained soil with organic matter; tolerates alkaline desert soil but prefers amended, moisture-retentive ground.
- Native range
- South America (Argentina, Brazil, Paraguay); widely naturalized
- Best used as
- Fast screen/cover for fences, trellises, and arbors, Butterfly (host plant) garden, Ornamental flowering vine
- Wildlife
- Important larval host for Gulf fritillary and other longwing/heliconian butterflies; flowers attract bees and the edible orange fruit is taken by birds.
- Toxicity
- Foliage and unripe fruit contain cyanogenic compounds and are mildly toxic if eaten in quantity; ripe fruit pulp is edible but bland. Keep pets from grazing the leaves.
How to grow Blue Passion Vine in Tucson & the low desert
Watering
Water 1-2 times per week in summer heat; do not let it dry out completely during flowering. Mulch the root zone to keep it cool and moist.
Fertilizer & nutrients
Moderate feeder. Apply a balanced fertilizer in spring and again mid-summer; periodic light feeding supports continuous bloom and lush foliage.
Pruning & care
Prune in late winter/early spring to control its rampant growth, remove frost-damaged stems, and thin tangled growth. Remove unwanted suckers, which can emerge several feet from the plant.
Notes
Vigorous and can sucker and self-seed aggressively; can become weedy/invasive in mild climates, so site it where suckers can be managed. The most cold-hardy commonly grown passionflower, making it well suited to Tucson's occasional freezes.
Sources: University of Arizona Cooperative Extension (Pima County passionflower references); Arizona-Sonora Desert Museum / Spadefoot Nursery (regional passionvines); Wikipedia (Passiflora caerulea); Gardenia plant database