Cup And Saucer Purple

20 Seeds

Seeding Cup and Saucer 'Purple' (Cobaea scandens), also known as Cathedral Bells, is a bit more hands-on than typical annual flowers but very rewarding. This vigorous climber produces stunning bell-shaped purple flowers with green “saucers” and can cover trellises, fences, or arches in one season.

Here’s how to grow it from seed successfully:

🪻 Cup and Saucer Vine 'Purple' (Cobaea scandens) – Seeding Guide

📅 When to Sow

Indoors (recommended):

• Sow 10–12 weeks before last frost

  • Example: If last frost is late April, sow in January–February

Outdoors (not recommended for cold climates):

• Only sow after all danger of frost, and expect later flowering

🌱 How to Sow

Seed Prep (important):

• Scarify seeds lightly with sandpaper or nick the seed coat

• Soak in warm water for 12–24 hours before sowing
  (This helps break dormancy and improves germination)

Sowing Instructions:

• Sow 1 seed per pot (they dislike root disturbance)

• Lay seed on its edge (not flat) to prevent rotting

• Cover lightly with ¼ inch (6 mm) of moist soil

Containers:

• Use deep pots or modules to accommodate long roots

🌡️ Germination Conditions

• Temperature: 70–75°F (21–24°C)

• Time: 14–30 days (can be erratic—be patient)

• Keep soil consistently moist but not soggy

🌞 Light & Growth

• After germination, place in bright light or under grow lights

• Harden off seedlings before transplanting outdoors

🌿 Transplanting Outdoors

• After last frost, when nights are consistently above 50°F (10°C)

• Full sun is best (can handle some afternoon shade)

• Rich, well-draining soil

• Provide support immediately (trellis, arch, fence)

Spacing:

• 12–18 inches apart

🌸 Bloom Time

• Blooms mid- to late summer through frost

• Can reach 10–20 feet in a single season

• Attracts bees and hummingbirds

🌿 Tips

• Regular watering and light feeding support rapid growth

• Mulch to retain moisture

• Deadhead to prolong bloom (though seed set is uncommon in short-season areas)

• In warm climates (zones 9–11), it may overwinter as a perennial