Coral oleaster

Family

Elaeagnaceae

Habit

Shrub

Height

4.5 m

Spread

5 m

Growth

fast

Lifespan

120 years

First yield

after 5 years

Yield per plant

up to 10 kg a year

Yield in cultivation

up to 5 t/ha

Energy yield

450 kcal per m² a year

Hardiness

zone 3–8

Shade tolerance

light shade

Soil

Sand, Silt, Loam

Soil moisture

very dry – very moist

pH

5 – 7.5

Synonyms

Goumi, Ölweide

Times apply to the northern hemisphere in a temperate climate and shift with altitude and cultivar.

Edible: The fruits are round, pea-sized drupes of five to ten millimetres, dark red when fully ripe and covered in silvery stellate scales. They ripen from September and stay on the shrub into November; cropping is usually very heavy. Unripe they taste harsh and astringent, fully ripe tart-sour to pleasantly sweet — cultivar choice matters more here than with most wild fruits. Around 20 mg vitamin C per 100 g, up to 12 per cent total sugar and 1.5 per cent fruit acid are documented, alongside protein, phosphorus, potassium and oils. Processed they give mixed-fruit jams, juices, fruit leather and liqueurs; the flowers too can be steeped for aromatic liqueurs. Harvest is by picking; with cultivars, shaking cut branches also works.

Medicinal: Flowers: astringent, cardiac, and stimulant properties Seeds: beneficial for coughs, oil for lung issues Fruit: abundant in minerals, vitamins (especially ACE), flavonoids, bioactive compounds, and essential fatty acids; boosts heart health, possesses anti-cancer attributes

Other uses: The chief secondary use of autumn olive is its soil work: through symbiosis with nitrogen-fixing actinomycetes it enriches even lean, sandy raw soils and makes them usable for more demanding neighbours — which is why permaculture plantings set it among fruit trees as a nurse shrub and cut it back later. As an undemanding pioneer it suits screening plantings, free-growing hedges, banks and roadside greenery; drought and salt tolerance make it interesting for difficult sites. In larger gardens it also works as a specimen, with intensely fragrant bloom in late April and silvery foliage. Its wood is only moderately durable and spiral-grained but serves for turning and yields fuel and biomass.

Site: Full sun gives the best fruit set, light shade is still tolerated. Almost any free-draining soil will do; it dislikes shallow calcareous ground. Its distinguishing feature is the symbiosis of its roots with nitrogen-fixing actinomycetes: it thrives on very poor raw soils and improves the site for neighbouring plants — in permaculture it is placed among fruit trees for exactly that. Established plants are drought- and salt-tolerant, so usable near roads. A broadly spreading shrub of about four metres, barely thorny and without suckers; allow three to four metres. Restraint is advisable near valuable dry grassland and xeric habitats: birds carry the seed far, and the added nitrogen changes such sites. Care: Pruning is unnecessary, though hard cutting back is tolerated; remove dead branches as the opportunity arises. Do not feed — it supplies itself through the root nodule symbiosis. No diseases or pests are known. Check the cultivar: several in the trade are self-sterile, among them Fortunella and Sweet'N-Tart, in which case a second, simultaneously flowering shrub is needed. In extreme winters frost damage into the wood can occur.

The species can be raised from seed: stones are washed out of the ripe fruit, stratified and then sown in a sheltered outdoor bed or an unheated frame. Seedlings come out variable, which is immaterial for hedges and pioneer plantings. To keep a particular fruit quality, propagate vegetatively: softwood cuttings in June or July root reliably, hardwood cuttings in winter are the simpler alternative. Pollination matters — several commercial cultivars are self-sterile, among them 'Fortunella' and 'Sweet'N-Tart'; they need a second shrub flowering at the same time. Self-fertile selections such as 'Garnet' manage alone but also crop more heavily in company.

Autumn olive comes from East Asia and is not native to Central Europe, so no reliable species counts exist for its value to local insects. What is documented is that its flowers carry abundant nectar and are worked by both honeybees and wild bees, making it a productive bee forage plant. Birds readily take the numerous red fruits, which aids its spread and has caused serious naturalisation problems in North America. Through root nodules it lives in symbiosis with the actinomycete Frankia and fixes atmospheric nitrogen, to the benefit of neighbouring plants.

Special features: drought+(sea)wind+pruning tolerant, very aromatic flowers that are very popular with (wild+)bees and butterflies, improves the soil and increases the yields of surrounding plants by 10%, prefers sandier, alkaline, nutrient-poor soils; one source states up to 40kg of fruit per bush.

East Asia: Japan, north-eastern China, Korea and the Himalaya, where autumn olive occupies open woodland, woodland edges and hill country. It was introduced to North America in the 19th and 20th centuries for reclaiming mined land and for erosion control and has naturalised across much of the eastern and central United States; there it counts as invasive, because bird dispersal and nitrogen fixation let it overgrow open, nutrient-poor sites quickly and alter their nutrient balance. In Central Europe it is planted as a fruiting and pioneer shrub and escapes only occasionally so far; it is not on the EU list of invasive alien species of Union concern.

In its homeland autumn olive grows in open to denser woodland and along woodland margins of lowlands and hills. As a pioneer it is geared to open, disturbed ground: its roots live in symbiosis with nitrogen-fixing actinomycetes, visible as small brown nodules, so it thrives even on very poor raw soils and improves the site for its neighbours. It is light-hungry, tolerates light shade, takes a great deal of drought and salt, and does particularly well on loose, sandy soils. It avoids wet ground and shallow calcareous sites.