Elaeagnus

Week 25 - ESC Project - The Polyculture Project

Paul Alfrey February 26, 2022

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This week the ESC volunteers have been busy completing a Permaculture Design Course organised by Green School Village, as part of their planned project activities. We’re looking forward to seeing their designs at the end of next week and what they come up with. We’ll feature some of them in next week’s post, along with the wrap up of the ESC project.

This post is going to focus on one of our favourite plant genera, Elaeagnus. When we think about Nitrogen-fixing plants, many of us might think of Elaeagnus which contains around 60 species of evergreen and deciduous shrubs. We’re going to look at three of our favourite plants and what might help us to decide which one to choose for any given design. For a closer look at how Nitrogen Fixation works see our previous post here.

Elaeagnus angustfolia – Oleaster, Russian Olive

Overview: A deciduous large shrub or small tree growing to approximately 7m high and 7m wide, it is the largest of the three Elaeagnus species featured in this post. Hardy to zone 2 it can tolerate part shade, salt and air pollution. It is drought tolerant with thorny branches although there are many named varieties some of which are thornless. Leaves are willow-like in appearance. Sweet-smelling flowers appear in June with yellowish-silvery fruits ripening in October. The plants begin to flower and fruit from three years old and are really tolerant of pruning. Fruits hang on the plant for much of the winter providing a valuable source of winter food for birds. The fruit is readily eaten and disseminated by many species of birds. This species is considered invasive in the United States.

Uses: Thorny habit makes this plant a great choice for hedges and tolerance to maritime exposure means it’s a good plant to consider in coastal regions. The flowers are attractive to bees and other beneficial organisms so may be used as a companion plant. We have used this plant as an understory shrub on a south-facing edge in our forest garden and to take advantage of its drought tolerance, in a dry bed on the outside of the property. In our experience, it is the most drought tolerant of the three species. Classified by USDA as being a high nitrogen fixer.

Elaeagnus x ebbingei – Ebbinge’s silverberry

E. x ebbinge in autumn. In severe winters there may be a degree of leaf loss

Overview: A medium evergreen shrub that is a hybrid species typically growing to 5m high and 5m wide but Hardy to USDA zone 5. Can tolerate deeper shade than the other two species featured in our experience. It is drought tolerant with smooth branches and stems that are a reddish brown in colour. Leaves are dark green, often with a silvery appearance. Flowers are scented and appear in the autumn with ripening fruit ready the following spring. Fruit production can be variable with this plant, possibly due to the fact it flowers at a time when there aren’t as many pollinators about, but more likely due to the fact that we regularly trim the ornamental bushes in our home garden. As Elaeagnus x ebbingei flowers and fruits most freely on the current year’s growth, if the plants are trimmed in the growing season, fruiting potential will be lost.

The fruit of Elaeagnus x ebbinge

Uses: The tender and soft shoots make excellent biomass and are trimmed and applied as mulch under the productive plants in the forest garden. The dense form means you can harvest a good quantity from pruning. Flowers in the autumn provide late nectar/pollen to pollinators. Fruits are attractive red berries produced in the spring and are very pleasant when fully ripe. High ornamental value, and evergreen, which is useful when creating a privacy screen. Can be used in hedging for this purpose. The dense, shrub-like form provides nesting habitat for birds. Makes an excellent stand-alone ornamental.

Elaeagnus umbellata – Autumn Olive

Overview: A large deciduous shrub growing 4.5m high and 4.5m wide, hardy to zone 3. It
tolerates part shade and is very drought tolerant. Branches are often thorny while leaves are bright green, silvery beneath. Yellowish white, fragrant flowers, are produced in May-June attracting many beneficial organisms. Round, silvery brown (ripening red) fruits appear in Sep-Oct, and it’s often a battle between us and the birds as to who gets them first. Although quite fiddly to eat, they are delicious when fully ripe and are sometimes cultivated exclusively for their edible fruit. There are many named cultivars. Plants can fruit in 6 yrs from seed. Like Elaeagnus angustifolia, this species is considered weedy in the U.S. The species is classified by USDA as being a MEDIUM nitrogen fixer

Uses: The plant is used as a nurse tree, when planted with fruit trees it is reported to increase the overall yield of the orchard by 10%. It’s a great hedging plant and is also fairly wind tolerant. A candidate for coastal regions as can tolerate maritime exposure. The fruit of E. umbellata is probably my favourite of all three plants and seems to reliably fruit prolifically. As the birds adore the berries, there is a significant increase in numbers to the garden when the berries are ripe.