Macleaya is a genus of flowering plants in the poppy family, Papaveraceae. Species in this genus are known by the common name of plume poppies and one in particular, M. cordata, is cultivated as an ornamental plant in many regions of the world. This plant is also used in traditional Chinese medicine and products containing plume poppy extract can be found in stores that stock herbal medicines and supplies. Before taking products from such stores, it is advisable to consult a doctor to check for contraindications.
Members of this genus produce large lobed leaves in a basal rosette. A tall stalk — reaching heights of up to six feet (two meters) — develops, with leaves protruding from either side of the stalk. The flowers are cream to white, produced in airy sprays that can last an extended period of time. Macleaya is a perennial genus and the plants propagate underground with the use of rhizomes, allowing them to spread readily when they are growing in good soil.
People in United States Department of Agriculture (USDA) zones three through eight can usually cultivate Macleaya in their gardens. These poppies like full sun and prefer rich, well-drained soil with a high moisture content. Working soil with compost and other organic material can help it retain moisture while promoting drainage and adding nutrition. These plants are commonly grown in massed or bedded plantings, or along borders. One thing to be cautious of with Macleaya poppies is their tendency to invade when grown in open spaces.
When cut, these plants produce a thick, yellow sap. This sap has insecticidal and bactericidal properties. As a companion planting, these plants can help keep insects away from the garden, and the sap is also used in topical preparations to keep insects off the skin. In Chinese medicine, the plant has historically been used to treat bacterial infections, although some studies indicate that it is toxic, and should be used with care.
Propagation can be accomplished with divisions of existing mature plants, an excellent option for gardeners who know people with overgrown Macleaya patches that need to be thinned. Cuttings can also be taken and used to produce new plants, and the plants can be grown from seed as well. Nurseries can carry seedlings or order them by request if customers need a new source for members of this genus. Garden exchanges can also be a resource for gardeners looking for new and unusual plants.