About Cup & Saucer
Cup and saucer vine (Cobaea scandens) is a fast-growing climber from South and Central America known for its large, bell-shaped flowers that resemble a teacup sitting on a saucer. Its blooms open greenish-white and deepen to a rich purple, attracting bees and hummingbirds throughout the summer. Perfect for trellises and fences, it thrives in full sun and adds dramatic vertical interest to the garden.
When to Plant Cup & Saucer Seeds
Sow seeds indoors six to eight weeks before the last frost date in your area. Transplant seedlings about two weeks after the last frost when temperatures consistently stay above 50°F.
In the warmer areas of zones 9 and 10 that have a long growing season, sow seeds directly outdoors after the last frost.
Where to Plant Cup & Saucer Seeds
Cup and saucer vine is a tender perennial vine in its native environment, so choose a spot with a warm, southern exposure or where it can receive some afternoon shade in hotter climates. Choose a location that allows this vine to climb, at the base of a strong trellis or other structure. In cooler zones, this vine will act as an annual.
How to Plant Cup & Saucer Seeds
Soak seeds for a few hours in a bowl of water. This will soften the outer shell of the seeds to aid in germination.
Fill your containers with seed starting mixture and moisten. Examine your cup and saucer vine seed and notice that the seeds are flat with a pointy tip on one side. Some say to place seeds on the surface, press it into the soil and cover with just a light dusting. Other gardeners insist that you poke the seeds into the soil with the pointy tip of the seed facing up. Bury the seed lightly with soil until you can see just the point tip emerging slightly from the soil. We have tried both ways and been equally successful. Either way, cover the pots with a dome or plastic to create some humidity. Keep temperatures steady around 60°F to 75°F with the help of a heat mat. Bottom water to keep the soil evenly moist but not saturated. Germination typically occurs in 10 to 25 days.
Once they germinate, remove the seedlings from the heat mat and put them under grow lights.
Whether you are transplanting or directly sowing outdoors, do so when all threat of frost has passed. Mix in two to four inches of compost into the soil and space plants 8 to 12 inches apart to allow room for growth. Plant at the foot of a sturdy arbor, trellis, or along the base of a fence. Cup and saucer vine will climb and cling to any rough surface, stretching up to ten to twenty feet tall, even higher in other cases, in the warmer zones of nine and above.
How to Care for Cup & Saucer
Water regularly to maintain even moisture without saturating the soil. Cobaea scandens thrives in well-draining, rich soil. Mix in some aged compost into the soil midseason. Mist plants regularly or hose them down to prevent red spider mites and aphids in dry conditions.
Naturally late blooming, cup and saucer vine blooms from late summer into fall. The flowers are great for bouquets and should be cut when freshly opened. Briefly dip the stem ends in boiling water for longer vase life. Individual blooms can be floated in shallow bowls.