Caragana arborescens, also called the weeping pea tree or Siberian pea shrub, is a deciduous shrub or small tree native to Siberia and Manchuria. Growers in harsh northern climates plant the shrub as a windbreak, according to Purdue University. It also works well as a specimen plant, as a soil builder or as a hedge or screen, among other uses.
Weeping pea trees grow approximately 20 feet tall. They have rounded or columnar forms, smooth green bark and multiple stems. Their vivid green, pinnately compound leaves are arranged alternately, with eight to 12 oval-shaped leaflets to each leaf stem. The leaves are approximately 1 1/2 to 3 inches in length, while the individual leaflets vary between half an inch and an inch in length. The trees produce small yellow blossoms in early summer; later, legume or bean-like seedpods replace the flowers.
The weeping pea shrub Pendula, a Caragana arborescens cultivar, grows between 4 and 6 feet tall. It has stiff, downward-drooping branches and works well as a specimen tree, according to the University of Connecticut. Nana, a dwarf cultivar that grows between 3 and 6 feet tall, has heavy blossoms and thick, dense leaves. Walkeri, which grows between 10 and 15 feet tall, has fernlike leaves and narrow, pendulous branches. Many Caragana arborescens cultivars such as Pendula and Walker are grafted to standards to achieve a particular look or form.
Caring for Weeping Pea Trees
Weeping pea trees are cold hardy in United States Department of Agriculture hardiness zones 3 to 7. They propagate by layering, grafting, seed or root cuttings. This species thrives under difficult growing conditions and is tolerant of soil or air salinity, heavy winds, harsh cold and nutrient-poor, alkaline or dry soil. They prefer full sunlight but can also grow in partial shade. They grow best in well-drained, sandy, loam or clay soils. They also have a high tolerance for pests and diseases.
Benefits and Liabilities
Weeping pea trees produce edible pealike vegetables that can be cooked and eaten. They have a slightly bitter flavor but can serve as a source of nutrients when other foods are unavailable. They are also useful as food for poultry crops or wildlife. The University of Connecticut notes that weeping pea trees do not have outstanding ornamental qualities, however, and canker diseases occasionally infect weeping tree plantings. Some individuals may also be allergic to their pollen.