The Russian olive is a small deciduous tree or large shrub that is native to southern Europe and western Asia but has become widespread as an introduced species in North America. With its feathery silver foliage, tiny yellow flowers, and olive-like fruit, the Russian olive has ornamental appeal. But it is also considered an invasive weed in many areas. If you are trying to identify a Russian olive tree, the color of its leaves, flowers, bark, and fruit can be useful indicators.
The leaves of the Russian olive are perhaps its most identifiable feature. They are elongated, about 1-3 inches long, and silvery gray-green in color. The upper surfaces of the leaves are covered with small silvery scales, giving them a distinctive silver or grayish cast. When the leaves first emerge in spring, they may have a bit more of a greenish tint, but they soon take on the blue-gray coloring as they mature.
|Due to tiny scales covering leaf surface
|Most prominent in mature leaves
|Greenish in spring
|When first emerging
The silvery appearance helps distinguish the Russian olive from other landscape trees and shrubs. Very few plants have leaves of this distinctive blue-gray silvery shade. It makes the Russian olive easy to spot, even from a distance.
Russian olive flowers appear in late spring to early summer. They are tiny, only about 1/4 inch wide, with four yellow petals surrounding a central yellow stigma. The flowers grow in clusters, forming showy panicles about 2-3 inches long at the ends of branches.
|Petals and stigma
Although small, the profuse yellow flower clusters create a dramatic floral display. When in full bloom, the pendulous branches of the Russian olive appear almost dripping with the vibrant yellow blossoms.
The fruits of the Russian olive ripen in late summer or early fall. Resembling small olives, they are oval-shaped drupes about 1/3 inch long. The fruits start out green but mature to pale yellow or tan, often with a rosy blush.
|When first developing
|Tan with rosy blush
|As they ripen
The olive-like fruits are edible but not particularly tasty. They have a large pit and lack much flesh. Some people describe the flavor as unpleasantly mealy or astringent. However, birds relish the fruits and will quickly strip the branches of the ripe olive-like drupes.
Bark and Wood
On young Russian olive trees, the bark is smooth and grayish-green with lenticels. As the trees mature, the bark becomes irregularly ridged and furrowed vertically. The bark color also darkens to gray-brown or brown.
|On young trees
|On mature trees
|Furrowed and ridged
|Vertically on older trunks
The wood of the Russian olive is difficult to work but extremely durable outdoors. It has a yellowish color and unusual twisted grain patterns.
In addition to color, the growth habit of the Russian olive tree can aid identification. It has long, often spindly, whitish-gray branches. The crown shape is irregular but tends to be oval or rounded.
Russian olives are fast growing but short lived trees, only living about 25 years on average. They can reach 20-40 feet tall with an equal spread. When grown in dense thickets, they tend to self-prune lower branches as they stretch upward for light.
The species readily colonizes disturbed sites. It can spread aggressively by suckers and shoots to form dense thickets. It tolerates dry conditions, urban pollution, and saline soils.
Where is it Found?
Russian olives are hardy in USDA zones 3-9. They have naturalized over much of the United States and Canada after being introduced from Eurasia as an ornamental, windbreak, and wildlife plant. It is especially problematic in western states.
Look for Russian olives invading riparian areas, pastures, roadsides, urban lots, and areas along railroad tracks. They thrive best in full sun and adapt readily to both dry and irrigated sites.
The Russian olive is easy to identify by its blue-gray feathery foliage, yellow spring flowers, olive-like fruits, shaggy vertical bark, fast growth habit, and ability to spread rapidly in thickets. Now considered an invasive plant in much of North America, Russian olive identification can help with control and management efforts. Just look for that telltale silvery foliage.