Several species of trees can be described as sticky or glutinous. These trees grow in a range of sizes, shapes and colours and produce a wide variety of flowers and fruits. Some have sticky leaves, some produce glutinous sap while others have sticky fruits. When choosing sticky trees for your landscape, select species with soil, sun and moisture needs that best match the conditions in your planting site.
Some trees exude glutinous sap. The banyan (Ficus benghalensis) tree's sticky sap can be used for medicinal purposes and to make gum. Banyan trees grow to 80 feet tall with a 70-foot spread. These fast-growing evergreens have wide, pendulous canopies with descending branches that often hang to the ground. Banyans thrive in full sun to partial shade and well-drained to dry soils. The gumbo limbo (Bursera simaruba) has sticky sap. This semi-evergreen tree grows up to 60 feet tall with drooping branches. It has bronze, shiny, resinous bark and produces red berries with triangular-shaped seeds. Gumbo limbos grow well in full sun to partial shade and tolerate salt, drought, alkaline and sandy soils.
Certain trees produce glutinous fruits, seeds or pods. The Kentucky coffee tree (Gymnocladus dioicus) produces flat pods that contain seeds surrounded by sticky pulp. These North American natives grow to 60 feet tall with a wide 70-foot spread. They have pinnately compound, deciduous foliage that turns yellow in fall. Kentucky coffee trees grow best in full sun and well-drained soil. The tamarind tree (Tamarindus indica) produces sticky seed pods filled with a sticky, edible pulp used for flavouring drinks, condiments, curries and candy. This tropical tree grows from 80 to 100 feet with a 40-foot spread. It has bright-green, feathery evergreen foliage and blooms with yellow, orange and red flowers. Tamarind trees prefer full sun and moist, rich, well-drained soil.
Some trees have glutinous foliage or buds. The balsam poplar (Populus balsamifera) has serrated foliage with sticky, copper-hued undersides. This deciduous tree also produces sticky, aromatic buds that bloom in catkins. A member of the willow family, the balsam poplar's natural range falls across much of upper North America. It grows from 75 to 100 feet tall and prefers moist, cool soil. The eastern red cedar (Juniperus virginiana) has dark, lustrous, slightly sticky foliage. This evergreen grows to 50 feet tall with a narrow 15-foot spread. Eastern red cedars produce blue fruits that attract birds. They grow best in full sun and well-drained soil and tolerate drought and salt.
Shoots and Leaves
Several members of the alder (Alnus spp.) genus have glutinous foliage and shoots. The black or European alder (Alnus glutinosa) is named for its dark green serrated foliage that, in young trees, is coated with a sticky substance. This deciduous tree grows to 60 feet tall with a 40-foot spread. It prefers sun to partial shade and tolerates a range of soils, from wet to dry. Black alders bloom with yellow, red and brown flowers in catkins. The white alder (A. rhombifolia) produces shoots covered with sticky red hairs and has glutinous, deciduous foliage. It grows quickly from 75 to 100 feet, with a 40-foot-spread. White alders bloom with yellow flowers in spring and thrive in full sun to partial shade and moist, well-drained soil.