Plants
Passion Flower
Passiflora · Passifloraceae
The passion flower bears perhaps the most artful bloom you can grow in a pot on a balcony or terrace: a filigree wheel of rays in blue-violet and white that looks as if a watchmaker had built it. As a climbing container plant it conquers trellises and obelisks in summer, flowers tirelessly from June into September — and in winter needs only a bright, frost-free berth.
- Light
- Full sun; the more sun and warmth, the richer the flowering.
- Watering
- Generous in summer, sparing in winter quarters; the root ball must never dry out completely.
- Care level
- Medium
- Botanical
- Passiflora
Species choice matters at our latitude: the blue passion flower (Passiflora caerulea) survives light frosts down to about -10 °C against sheltered, warm walls in the Rhineland and can even be planted out there with winter protection — it dies back and reshoots from the rootstock. All other popular species, such as the purple Passiflora violacea or the passion fruit (Passiflora edulis), are strictly container plants.
The passion flower climbs with tendrils that wrap around thin rods, wires and strings in no time. In a pot, train it on an obelisk or fan trellis; on a warm summer day a vigorous plant gains several centimetres. The sunnier and warmer the spot, the more freely the flowers open — each lasts only one or two days, but the plant keeps pushing out new ones for weeks.
The classic care mistake is well-meant overwintering in a warm living room: there the plant grows leggy and gets infested with spider mites. Correct is a bright, cool berth at 5 to 10 °C — an unheated conservatory, a bright stairwell or a frost-free garage with a window. Before bringing it in, cut the shoots back by about two thirds.
After pollination, orange-yellow egg-shaped fruits form. On the blue passion flower they are edible when ripe but bland and mealy; unripe fruit and all green parts of the plant, however, contain cyanogenic compounds and are considered mildly toxic. The true passion fruit comes only from Passiflora edulis, which needs a long, warm summer.
In floristry the passion flower appears mainly as a potted gift plant on a trellis — it arrives via the auction in flowering quality from spring into summer. Its symbolism makes it a popular gift for communion, confirmation and church occasions; as a cut flower, though, the short-lived bloom is unsuitable.
Is Passion Flower toxic to children and pets?
- Children
- Mildly irritating
- Cats
- Mildly irritating
- Dogs
- Mildly irritating
Leaves, shoots and unripe fruit contain cyanogenic glycosides and are considered mildly toxic to people, dogs and cats. Ripe fruits of the blue passion flower are edible but bland; children and pets should not nibble green plant parts or unripe fruit.
Typical symptoms: After eating larger amounts: nausea, vomiting, abdominal pain and drowsiness.
In an emergency:call the German poison control centre in Bonn on +49 228 19240 (24/7) — for pets, contact an emergency vet directly. This information does not replace medical or veterinary advice.
Overview: toxic & non-toxic plants for cats, dogs and children
Care
- 01Fully sunny, warm position, ideally rain-sheltered against a south wall.
- 02Water generously in summer, daily on hot days; still avoid waterlogging in the pot.
- 03Feed weekly from May to August; the passion flower is a heavy feeder.
- 04Provide a support of thin rods or wires and guide the shoots at first.
- 05Overwinter bright and cool at 5 to 10 °C; cut back by two thirds beforehand.
- 06Passiflora caerulea can be planted out in mild locations with thick winter protection.
Frequently asked
- Is the passion flower hardy?
- Only partly. The blue passion flower (Passiflora caerulea) tolerates around -10 °C briefly in sheltered spots and can be planted out with thick winter protection in mild regions like the Rhineland — it then dies back above ground and reshoots in May. All other species must overwinter bright and frost-free at 5 to 10 °C.
- Can I eat the fruits of my passion flower?
- The ripe orange-yellow fruits of the blue passion flower are edible but taste bland and mealy — they have little in common with a passion fruit. Important: unripe fruit and all green parts contain cyanogenic compounds and should not be eaten. True passion fruit grows only on Passiflora edulis.
- Why does my passion flower not bloom?
- The most common reasons: too little sun, too much nitrogen (lots of foliage, no flowers) and winter quarters that are too warm, weakening the plant. Passion flowers bloom on new wood — so a hard cut back in autumn or spring does no harm but encourages flowering. A fully sunny spot and potassium-rich feed usually bring it into bloom.
- Is the passion flower toxic to cats and dogs?
- Mildly toxic: leaves, shoots and unripe fruit contain cyanogenic glycosides that can cause nausea, vomiting and drowsiness if larger amounts are eaten. Keep nibbling cats away from the plant; occasional sniffing is unproblematic.
- How do I overwinter a potted passion flower correctly?
- Before the first frost, shorten the shoots by about two thirds and place the plant bright and cool at 5 to 10 °C — for instance in an unheated conservatory or bright stairwell. Water only enough to keep the root ball from drying out, and do not feed. From May, after the last frosts, it can go back outside.