Cleome hassleriana, or Spider Flower, is a glandular-pubescent, erect annual, native from Argentina to SE Brazil. This strongly scented plant will reach up to 5 feet (1.5 m) tall in containers or in the landscape. Leaves are palmately compound with 5-7 leaflets. The long, acuminate leaflets bear short spines at their base. These are very easy plants to grow. In USDA zones 8-11 they are considered hardy annuals and in all other zones (4-7) they should be considered as tender annuals.
Blooming Time: Flowers are borne in showy bracted racemes. The 1-2 inch (2.5-5 cm) wide flowers with 2-3 inch (5-7.6 cm) stamens give this flower its spidery appearance. They provide a distinctive accent to any collection and have a long blooming period in zone 7. Flowers are pink, mauve or white.
Culture: Cleome hassleriana needs full sun to very light shade and does best in a well-drained soil mix. In the greenhouse, we use a soil mix consisting of 1 part peat moss to 2 parts loam and sand. Plants are well watered and allowed to dry slightly before watering again. We fertilize the plants monthly in containers. In the landscape, these plants are very drought tolerant and should only be watered in severe drought conditions or as needed for continued growth. Being annual, it is a prolific seed producer. In milder climates, it will reseed itself. Care should be taken because it can become very weedy if left unchecked.
Propagation: Cleome hassleriana or Spider Flower is best grown from seed.
Cleome hassleriana was featured as Plant of the Week February 19-25, 2010.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2017 All rights reserved.