Cerinthe major atropurpurea , featured at Sissinghurst Castle in England, is actually a native of the Greek Islands. This hard to find annual is definitely a much sought after easy to grow annual from seed. Not available as transplants, you can get the seed from Renee’s Garden Seeds.
An unusually colored flower with indigo-violet drooping flowers that dangle gracefully above gray-green leaves. A great plant for containers or for the border, it is easy to start from seed.
Pop in the seeds and a few days later, juicy succulent-like shoots appear above the soil and quickly grow into robust plants for transplanting. Wonderful as cuts for fresh flower arrangements, you can always spot them at Sissinghurst in the UK as their signature plant.
Also known as honeywort, the flowers attract bees and hummingbirds. The one inch long flowers produce honey-flavored nectar, probably leading to its common name. As the plant matures, the bracts change from green to purple to blue. Deadhead to encourage continued bloom. If you wish to use honeywort as a cut flower, the ends of the stem need to be either flamed or dipped in hot water.
Cerinthe is a good filler plant, with its blue-green foliage and succulent texture contrasting nicely with other greens in the garden. To bring out the other colors in the bracts, such as golds, yellows, bronzes, interplant cerinthe with plants that have purple or bronze leaves, such as Caramel Heuchera or Euphoriba ‘Chameleon’. Reseeding in my garden happens frequently which I encourage.
TO START OUTDOORS
In spring, once all danger of frost is past, sow seed directly where plants are to grow in ordinary well-drained soil in full sun. In mild climates, Cerinthe can also be sown in fall for spring blooms. Poke the large seeds into the soil about 3⁄4 inch deep and 4 to 6 inches apart and firm soil gently over them.
TO START EARLY INDOORS
Start seeds indoors in 4 inch pots about 4 to 6 weeks before last frost date. Keep moist, but not soggy and provide a strong light source. Once seedlings are 4 to 6 inches tall, acclimate to outdoor conditions and transplant into a sunny spot, in well-drained garden soil. Thin or transplant seedlings 8 to 12 inches apart. Avoid disturbing seedling roots.
GROWING NOTES (from Renee’s Garden Seeds)
Cerinthe prefers full sun, but can take dappled shade, although plants will be more rangy in habit. Be patient; plants are undistinguished until they come into bloom. By late spring, the dramatic blue bracts will turn more purple at the tips, then the clusters of purple bells trimmed with a white edge unfurl. Grow near pastel cleome or cosmos for an exciting color contrast.
Today, it is not commonly offered commercially in the U.S. The plants are not particularly stunning from a distance unless plant in mass; the enchanting flowers are best appreciated up close as the coloring is subtle. The variety ‘Purpurascens’ is the most commonly available type and was selected for its stronger coloration than the species.
Click here to see my recent article on Cerinthe in The American Gardener.