Cleome or Spider Flower (2024)

An easily grown annual native to South America, cleome (Cleome hassleriana synonym C. pungens, C. spinosa) is a favorite in Southern gardens. The delicate pink, rose, purple, white, or bicolor spider-like flowers, along with the spidery seedpods, give it the common name, spider flower. It grows best in average, well-drained soils and in full sun to light shade. Somewhat drought tolerant, cleome will benefit from supplemental irrigation during dry periods. Many new dwarf hybrid cultivars (Cleome hybrida) have been bred for more compact growth habits and prolific blooms.

Cleome (Cleome hassleriana) mixes well with other summer annuals, such as sunflowers (Helianthus annus).
Barbara H. Smith, ©2017 HGIC, Clemson Extension

Height/Spread

Depending on the cultivar or series, cleome will range in height 1½- to 5-feet tall with a 1- to 2-feet spread. The newer dwarf cultivars are 1½- to 4-feet tall by 1- to 2-feet wide, making them a good choice for smaller areas and containers.

Ornamental Features

Cleome bloom from June until frost. The 4- to 8-inch spider-like blooms start at the bottom of the stalk and move upwards. Deadheading, the removal of the spent flowers, is not necessary. The flowers are followed by thin green seedpods that ripen to brown and split open to disperse the small seed. Older cultivars, such as the Queen series, produce viable seed and will potentially self-seed in nearby areas. Newer hybrids are sterile and do not produce viable seed.

The thin, spidery green seedpods give spider flower its common name.
Barbara H. Smith, ©2017 HGIC, Clemson Extension

The flowers are followed by thin green seedpods that ripen to brown and split open to disperse the small seed.
Barbara H. Smith, ©2018 HGIC, Clemson Extension

How to Grow

Seeds may be sown directly in the landscape after the fear of frost has passed. The soil temperatures should be 70 to 75° F. Thinly sow the seeds 4- to 6- inches apart and cover with ¼-inch of soil. Keep the bed moist, but not wet, until germination. Seedlings will appear in 7 to 14 days. Depending on the cultivar, thin the seedlings to a spacing of 10- to 15-inches apart. Seeds may also be started indoors 6 to 8 weeks before transplanting outside. Cleome will bloom 70 to 80 days after germination.

The Queen series seed have a better germination rate if chilled for 4 to 5 days prior to planting. To chill the seed, evenly spread them on a moist, not wet, paper towel, fold, place inside a zip-lock bag, and keep in the refrigerator. This series reseeds itself and should be considered for areas where the gardener wishes for it to return year after year. The hybrid Sparkler™ series seeds do not need to be chilled prior to germination. The Spirit™ series has the ability to self-sow but may be established either by planting seed or by buying plants from a nursery. As the ‘Linde Armstrong’ and Señorita® series flowers are sterile and do not produce viable seeds, transplants must be purchased and planted into the garden.

After planting, add a thin layer of 1 to 2 inches of mulch to help retain moisture as well as discourage weed seeds from germinating. Due to the strong taproot, staking is usually not necessary.

Landscape Use

Cleome works well in borders, background plantings, masses, cutting gardens, and containers. It contrasts well when combined with many other summer annuals, such as sunflowers, zinnias, cosmos, salvia, or celosia. Cleome makes a better impact in the landscape when planted in masses 2 to 3 feet wide. It is beneficial to plant other smaller annuals in front of the taller cleome cultivars as they tend to have bare lower stalks. Cleome is deer and rabbit resistant. The flower nectar attracts hummingbirds, butterflies, bees, and other pollinating insects. Another unusual visitor attracted to cleome is the hummingbird moth that visits the flowers at dusk.

Smaller cultivars, such as the Sparkler™ and Senorita® series along with the ‘Linde Armstrong’, have a more compact growth habit and are excellent additions to annual container combinations.

Problems

Overall, cleome is a tough annual. There are no serious insect or disease problems. Aphids, spider mites, and whiteflies can be a problem. It is susceptible to powdery mildew and rust in hot, humid climates; therefore, it is important to space the plants properly to allow better air circulation to help prevent infection.

To avoid disease issues the next year, remove dead plants after they are killed by frost.

Cultivars

´Helen Campbell´ has dramatic, pure white flowers and will reach a height of 4-feet and a width of 1- to 2-feet. The Royal Horticulture Society awarded this selection the prestigious Award of Garden Merit in 1993.
´Linde Armstrong´ is a dwarf, compact, odorless, and thornless grower with pink flowers that will reach 12- to 18-inches high and 12-inches wide. It is an Athens Select hybrid with sterile seed and is produced from cuttings. Transplants must be planted in the garden.

The Queen series is the oldest of the series bred cleome. The flowers are easily pollinated and produce viable seeds. The resulting seedlings will be similar to the parent plants, but not necessarily the same color. It is the tallest at 3- to 5-feet tall by 1- to 2-feet wide and will self-seed aggressively. The foliage has a strong odor and sticky leaves with spines at the base. Mixed color seed blends are available along with individual color cultivars.

´Cherry Queen´-bright, cherry rose flowers
´Rose Queen´-pastel, rose-pink flowers