Giant Granadilla Seeds

Giant Granadilla — Passiflora quadrangularis

With the Giant Granadilla (Passiflora quadrangularis) you grow the queen of passion fruits yourself. It bears the LARGEST fruit of all Passiflora — up to 30 cm long and 3 kg. Spectacular pink-purple flowers with contrasting filaments. Climbs with tendrils up to 15 m, ideal for pergolas and trellises in summer. Ripe fruit tastes of honeydew and passion fruit.

What's in the box

• 12 seeds Passiflora quadrangularis — tested for germination
• Illustrated growing guide in 8 languages (on the seed card)
• Minimum shelf life: 2 years from packaging date

Growing in brief

• Prep: soak seeds 24 h in lukewarm water
• Sowing: in loose, moist seed compost
• Temperature: 25-28 °C
• Germination: 3-6 nach Vorbehandlung weeks

Position & care in detail

• Light: full sun
• Humidity: high
• Substrate: humus-rich, well-draining
• Watering: plentiful during growth
• Feeding: March to September weekly
• Wintering: Frost-tender — minimum 12 °C

Sowing date & timeline

The ideal sowing date depends on the plant type.

Indoors sowing is possible year-round if heat mat and grow light are available. January to April is optimal: after germination the seedling can grow vigorously through spring/summer before light declines in autumn.

Directly outdoors only for frost-hardy species and after mid-May. Frost-tender species should first be raised in pots indoors, then hardened off after mid-May before being placed outdoors.

Pot choice & transplanting

Pot size and transplanting evolve with the plant:

• Sowing: 6×6 cm seed tray per seed or tray pots. Use low-nutrient seed compost.
• Seedling: prick out at 2-3 true leaves into a 9 cm pot with nutrient-rich compost.
• Established: repot every 1-2 years into a pot 2-3 cm larger. Mature plants need 5-30 L pot volume depending on the species.

Tips & tricks

• Use a heat mat: bottom heat at 25 °C speeds germination by weeks
• Mini greenhouse: cover seed tray with a transparent lid or cling film — keeps humidity high
• Prefer fresh seed: the fresher the seed, the higher the germination rate — sow soon after delivery
• Soak seeds 24 h, lightly scarify if needed
• Sturdy support from the start — produces 3-4 m shoots in year 1
• Winter-prune and keep cool (12-15 °C)

Good to know

• Native range: Tropical South America
• Height: 15 m, in a pot 3-5 m
• Bears the LARGEST fruit of all passion fruits — up to 30 cm, 3 kg
• Spectacular pink-purple flowers with contrasting filaments
• Climbs with tendrils up to 15 m — ideal for pergolas
• Ripe fruit: honeydew meets passion fruit

Seed storage

Unopened or leftover Saflax seeds keep for 2 years if stored correctly. Keep dry, cool (vegetable drawer in fridge) and in the original packaging — moisture drastically reduces germination. Test germinability before each sowing: 5 seeds on moist kitchen paper in a covered plastic dish at 22-25 °C — if 4-5 germinate, the rest are reliable.

FAQs

How long does germination take?
Typically 3-6 nach Vorbehandlung at 25-28 °C. Bottom heat (heat mat) shortens germination significantly, often by half.

Can it grow outdoors?
In summer yes, in a sheltered, semi-shaded position. Bring indoors before first frost, min. 12 °C in winter.

How fast does it grow?
Slow in the first year (establishment phase), then notably faster from year two with optimal care and the right position.

Do I need special tools?
A simple seed tray, compost and a bright position are enough. A heat mat (~CHF 30) and a mini greenhouse noticeably improve germination but are not mandatory.

What if seeds don't germinate?
Patience — many exotic species take 4-12 weeks. Check temperature (heat mat!), substrate moisture (evenly moist, never wet) and whether the seeds require stratification or scarification. Saflax seeds are tested for germination before dispatch.

Will it bear fruit here?
Difficult — needs 25 °C in summer and pollination. Without hand-pollination rarely fruits. As flowering climber it's sensational though.

How big do the fruits get?
In their homeland up to 30 cm and 3 kg — the largest Passiflora fruit overall. Rarer and smaller here.

How best to store leftover seeds?
In the sealed original packet, dry and cool (vegetable drawer of fridge at 4-8 °C). Germinability is preserved through the full 2-year shelf life. Reseal immediately after opening and acclimatise to room temperature before sowing.