Standing up to 4 feet tall, the cleome is the perfect annual backdrop for your low-growing bedding plants. Tall stalks covered in lace-shaped green leaves terminate in a ring of small blooms that top the stalk like a crown. Cleome grows prolifically in most areas of the United States, so you are sure to find a species that will become a garden delight for you.
Cleome has stalks of varying heights based on the species. Stalks are covered in long, slender leaves with pointed ends, grouped in sets of three. Blooms are irregularly shaped, typically in mauve, pink, violet, or white shades, and appear in a ring at the top of the stalk.
The cleome prefers full sun but will tolerate afternoon shade. Choose a location with well-drained soil or prepare the soil before planting by cultivating up to 3 inches of organic matter to a depth of 8 inches. This process improves drainage and creates a healthier bed.
When daytime temperatures warm up in the spring, cleome seeds may be sown directly on site. Scatter the seeds and gently press down with your palm to settle them. Water well. Germination occurs in one to two weeks at 75 degree Fahrenheit temperatures. Thin seedlings to 12 inches apart and pinch the tops to create a more rounded plant. If purchased in containers, smaller varieties can be planted 12 inches apart; 24 inches is preferable for the taller species.
Water when soil becomes dry on the surface and increase water if necessary during dry periods. Some species of cleome are drought resistant, but pay attention to the needs of your specific plant in response to your climate. Apply a balanced, slow-release fertilizer midsummer, per manufacturer directions, and massage into the topsoil of the bed. Also provide a 2- to 3-inch layer of organic mulch, such as pine bark, to retain moisture. Remove spent blooms to encourage new growth and more flowers.
Cleome hasslerana, the spider flower, grows to 48 inches tall and produces pink, white or purple shaded blossoms. Take care with this species, however, as it has two possible drawbacks. The first is the prickly thorns that appear on its stalks. The second is its predilection to reseed, or produce volunteer plants that behave as perennials and can quickly overtake a small space. Senorita Rosalita is a lower-growing cleome that nicely solves the two cautions listed above. Thorn-less and sterile, you won't be bothered by finger pricks or pesky volunteers from these pink-lavender beauties.