Cup-and-saucer Vine Cobaea scandens

The cup and saucer vine is a tender sub-tropical perennial in the phlox family (Polemoniaceae).  It is native to Mexico and tropical South America.  The genus name refers to Bernardo Cobo, a Spanish missionary and naturalist in Mexico and Peru.  The specific epithet means climbing.

The easy-to-grow vine prefers moist, well-drained soils in full sun.  In its frost-free native habitat, the vine grows rapidly to 30-40 feet.  Otherwise, it grows 10-20 feet tall and 3-6 feet wide annually.  Provide some shelter and afternoon shade in hot summer climates.  Too much fertilizer will promote foliage instead of flowers.  Provide good air circulation to minimize mildew in humid environments.  Propagation is by softwood cuttings, or seeds started indoors or by direct seeding outside.  The seeds will sprout inside after 14 days if the pots are kept warm between 68-72 degrees Fahrenheit.  If the vine survives as an evergreen, prune in late winter to shape it and to remove diseased growth.

The showy purple flowers with a saucer-like green calx are 2 inches long, last about 4 days, and have a musky fragrance.  The Royal Horticultural Society has presented it with the Award of Garden Merit.

Grow along a fence, arbor, wall, or trellis.  Plant in a 3-gallon container or near a path to enjoy the fragrance during the summer.

Insects, Diseases, and Other Plant Problems:  No serious problems. May attract some aphids and spider mites.