I've admired photographs of cleome flowers gracing cottage-style garden borders, but I've never included them in my annual/perennial border until I came upon them growing in 5-gallon pots at Home Depot this past June. By June, all of the spring wild flowers I planted last January from seed had faded and these tall plants with their eye-catching "spider-like" flowers were just what I needed to add a bunch of color and height to my summer garden.
Commonly known as "spider flowers," this old-fashioned flowering plant has been a favorite garden flower since Victorian times. A prolific reseeding annual, which means the plant dies back at years end, but new plants grow from the seeds that fall to the ground the following season. Cleomes thrive in most soils, as long as they are well-drained. Once established, they don't require a lot of water and can be planted along with companion plants that also have low watering needs. They prefer a sunny location, but can tolerate partial shade, especially in areas that have strong hot afternoon sun. If planted in too shady of an area, their stems will grow long and lanky and they may not produce as many flowers, or none at all.
Blooming in the summer, cleome flowers come in shades of pink, lavender or white and the plant itself can grow up to 4-5 feet high. There are also new dwarf varieties that only grow 2-3 feet in height. As the plant grows, you can pinch off its bottom growth and lower leaves if you want it to grow taller, or prune the center growth for a more bushy plant. Deadhead most of the flowers as they fade, but leave a few on the plant and let them go to seed to plant for next season, or let the seeds fall into the garden — once you have a cleome, you will always have them in your garden.
This late in the season, you may not find blooming cleome plants at garden centers, but you can purchase cleome seeds to plant for next season. Plant the seeds outdoors in late winter or early spring. Cleome seeds take about 10 to 14 days to germinate and they need sunlight to do so. Press the seeds very lightly into the soil, keeping them mostly exposed, and water frequently, so that the soil stays moist while they take hold. As the tiny plants grow, thin them out and replant them about 12 to 18 inches apart. Fertilize with a balanced organic fertilizer as they mature to encourage growth. Cleomes usually bloom about 75 days after they begin growing. Both the tall and dwarf varieties also do well as container plants.
It seems that all my favorite plants and flowers attract butterflies, bees and hummingbirds and cleomes will keep your garden dancing with these creatures all summer long. I've also read that the somewhat unpleasant smell from the cleome leaves will keep unwanted pests away, or maybe the flowers appearance makes the pests believe they are really huge spiders!