1153 Elaeagnus angustifoliaCommon Names: Russian olive, oleaster, silverberry, thorny elaeagnus Family: Elaeagnaceae (oleaster Family)
Russian olive (so named because of a resemblance to the unrelated true olive (Olea europaea) is a deciduous small tree or shrub with spreading reddish brown branches clothed in silvery scales. Branches often have short, sharply pointed spinelike stems that eventually grow into typical branches. The shrub can get up to 20 ft (6 m) tall and just as wide, but is usually about half that size. Leaves are lance shaped and about 4 in (10 cm) long. They are dark green above and silvery scaly beneath. Some cultivars (‘Quicksilver’, for example) have leaves that are silvery both top and bottom. The flowers, produced in early summer, are strongly fragrant, yellowish white and about a half inch (1.5 cm) long. The single-seeded fruits are silvery scaly, juicy and edible, very much like the closely related gumi (Elaeagnus multiflora), only yellow instead of red. (However, ‘Red King’ is a cultivar with red fruits.)
Elaeagnus angustifolia is native to China, Central Asia, southern Europe, and the Himalayas where it grows in dry woods, thickets, abandoned fields and waste areas. It has been cultivated in Europe for centuries. Russian olive has escaped cultivation and established itself throughout all parts of North America except the southeastern corner.
CultureRussian olive likes any kind of well drained soil and is tolerant of coastal, even beachfront conditions. Like its other relative, silverthorn (E. pungens), Russian olive suckers freely and can be a handful to keep pruned and within the bounds of your choosing. Light: Russian olive does best in full sun. Moisture: Russian olive tolerates dry conditions and does best in light, sandy soils. Hardiness: USDA Zones 2 - 7. Propagation: Greenwood cuttings taken in spring can be started in sand. Suckers that have developed their own roots can be dug and replanted. Russian olive is easy to start from seed and you may find that the shrub doesn’t even need your help to do so.
Russian olive tolerates salt spray, alkaline soils, urban and streetside conditions, and drought. Russian olive is a fast grower and prone to suckering. However, with attentive pruning it can be kept neat and tidy and makes a fine specimen shrub. Russian olive can be useful in a shrub border, especially one that is not supposed to be formal, since, absent pruning, this Ruski is definitely informal!
The delightfully fragrant (a little heady?) flowers can be appreciated from a considerable distance. The sweet fruits are relished by birds and other wildlife, and sometimes draw contentious flocks of noisy diners. People like them too, and use the juice in deserts, especially in the Far East.
Like the other species of Elaeagnus, Russian olive is capable of obtaining nitrogen from the atmosphere, something almost all other plants (with the notable exception of the legumes) cannot do. Nitrogen is essential for all plant and animal life and is a basic building block of all proteins. All plants must have nitrogen to grow and manufacture organic compounds. (Plants also need phosphorus, potassium and certain other elements, but unlike usable nitrogen, these are normally present in the soil.) Although nitrogen is the most abundant element in the atmosphere (it makes up 79% of the air), it cannot be used by plants in its elemental form. Nitrogen must be combined (“fixed”) with hydrogen to create ammonia before it can be taken up by green plants and thus enter the web of life. This process, “nitrogen fixation”, is carried out by free living bacteria in the soil or bacteria living in a symbiotic relationship on the roots of certain plants. Legumes, Elaeagnus spp., wax myrtle (Myrica cerifera) and just a few other plant species have nodules on their roots which contain their own nitrogen fixing bacteria and are thus able to obtain nitrogen without depending on it already being in the soil.
Another way that nitrogen is made available to plants is when decaying organisms (think fertilizers) release nitrates, which are then converted to ammonium ions by another type of bacteria also present in the soil. Yet another way to fix atmospheric nitrogen involves lightning strikes which break apart the nitrogen molecules in the air allowing them to combine with oxygen to form nitrites and nitrates which are then converted to ammonia by nitrifying bacteria in the soil.
Russian olive (Elaeagnus angustifolia) is considered an invasive, noxious weed in much of the U.S. and its cultivation is banned in several states. It spreads by seeds and suckering and the conscientious gardener should probably abstain from growing Russian olive except under the most controlled conditions.
Steve Christman 6/10/12; updated 8/18/12