Russian olive: Elaeagnus angustifolia

Russian olive is generally a shrub or may grow as a small tree. It may measure from 25 to 30 feet tall and be 8 inches in diameter. Some plants are armed with thorns. The bark peels in long strips and older trunks are deeply grooved.

Simple, alternate leaves are about 1.5 to 3 inches long and have a lance or oblong shape with smooth margins. The lower leaf surfaces are gray-white and dense with scales and brown dots. Russian olive flowers and sets fruit at 3 years of age. The cluster inflorescences occur in leaf axils and the light yellow, fragrant flowers appear after leaf emergence in early spring. Flowers bloom late into the spring season.

This shrub receives its common name from the plump, oval fruits that resemble olives. Ripened fruits are a yellowish red color, dry and covered with gray scales. Fruits are very abundant, mature in late summer and are consumed and dispersed by birds. The seed coats are resistant to digestion. Seeds may be viable for up to three years and will germinate over a wide range of environmental conditions. The shrub reproduces primarily by seed, but also will propagate vegetatively.

Russian olive is indigenous to Europe and western Asia. It was first planted in the United States in the late 19th century as an ornamental planting. Its invasiveness has become a great problem in riparian woodlands in the west, inhibiting growth of strong native trees such as the cottonwood. Russian olive spreads to form monocultures that changes hydrology, nutrient cycling and ecosystem structure. This invasive species is drought tolerant and will grow in temperatures ranging from -50 to 115 F.

Russian olive has been noted to escape cultivation in over 35 states and is declared a state noxious weed in several western states. Even up until the mid-1980s, extension and state forestry agencies subsidized distribution of Russian olive seedlings to private lands for wildlife usage in 16 of the 17 western states.

In moist soils, seedlings can be hand pulled without much difficulty. Continuous mowing may also give good control if conditions permit. Large shrubs cut or girdled produce new growth unless an herbicide is immediately applied. A cut stump herbicide application is the most effective method of control for large mature trees. The trunk or stem is cut close to the ground and within a few minutes herbicide is brushed on to the cambium layer of the cut.

Contact the weed board for control and chemical recommendations at 509-754-2011, Ext. 4710, or visit our website at www.grantcountyweedboard.org.