Thorny olive

Thorny olive: how do you recognise it?

Habit

Broad, dense shrub up to 3 m, with long, somewhat sprawling branches; sometimes thorny.

Leaves

Oval to oblong, 5–10 cm, leathery; glossy green above, silvery with brown scales below. Variegated forms with yellow.

Flower

Small, drooping, silvery-white tubular flowers in the leaf axils, in October–November.

Scent

Sweet and penetrating: you often smell the shrub before you see the flowers.

Fruit

A small, oval, reddish-brown fruit speckled with silver that ripens in spring; rather rare here.

Roots

Live together with bacteria that fix nitrogen from the air, so it grows even on poor soil.

Flowering: October–November · Harvest and fruit: April–May · Plants: April–May and September–October · Pruning: April–May

Why grow it?

• Evergreen leaves, often variegated yellow and green: colour in the garden all year round.
• Fragrant flowers in autumn, when little else is in bloom; a late food source for bees.
• Tolerates sun, partial shade and shade, wind and drought.
• Suitable as a dense hedge, windbreak or specimen.
• Few diseases and easy to look after.

Thorny olive: where does it grow best?

• Sun, partial shade or shade; variegated forms colour best in sun or light shade.
• Any well-drained soil: sand, loam or clay, acid to chalky.
• Dry to moist; once established it tolerates drought.
• As a hedge plant 60–80 cm apart; as a specimen allow 2.5–3 m of space.

Light

Sun, partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Dry or normal

Size

3 m tall, 3 m wide

Hardiness

Hardy (to -15 °C)

Goes well with

• Laurustinus: Evergreen and flowering from late autumn into spring: together a green, flowering hedge.
• Mahonia: Yellow, fragrant sprays in winter and just as easy in shade.
• Witch hazel: Takes over the scent in January–February, when the thorny olive has finished.
• Bergenia: Large evergreen leaves as underplanting.
• Dogwood: Red or yellow winter stems next to the variegated leaves.

Thorny olive: when and how to plant it?

Plant in April–May and September–October.

1. Plant in April–May or September–October.
2. Dig a hole twice as wide as the root ball and loosen the bottom.
3. Set the plant at the same depth as in the pot and firm the soil well.
4. For a hedge: plant 60–80 cm apart along a stretched line.
5. Water well, and during dry spells in the first year, including in a dry autumn.
6. Mulch around the base to keep weeds down.

Care

Water

In dry spells during the first year; rarely needed after that.

Feeding

Some compost or organic fertiliser in March, especially for a hedge.

Green shoots

On variegated forms, cut all-green shoots right back to their base as soon as they appear.

Mulching

A layer of wood chips around young plants keeps the soil moist and weed-free.

Thorns

Wear sturdy gloves when pruning.

Tip: On variegated forms, cut green shoots right back to their base straight away: they grow faster than the variegated foliage and will otherwise take over the shrub. Plant it by a path so you can enjoy the scent in autumn.

Thorny olive: when to prune it?

Pruning months: April–May.

When: Shape the shrub or hedge in April–May. Remove green shoots on variegated forms as soon as you see them.

How:

• Shorten overlong branches to just above a leaf or side shoot; this keeps the shrub dense.
• Trim a hedge with shears, slightly narrower at the top than at the bottom.
• Cut all-green shoots on variegated forms back to their base.
• It tolerates hard pruning and reshoots from old wood.

Caution: Do not prune hard in late summer, or you will remove the young shoots carrying the buds for the autumn flowers.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

In August–September: heeled cuttings of 10–15 cm in moist cutting compost under plastic. They root slowly: allow a few months.

Layering

In spring, peg a low branch into the soil and cover it; sever it after a year.

Thorny olive: how does it get through the winter?

Hardy to −15 °C: protect young plants.

• Hardy to about −15 °C: no problem in most Belgian winters.
• In severe winters or cold winds the leaves can brown or partly drop; the shrub reshoots in spring.
• In a cold, windy corner, protect young plants with fleece during their first winter.
• In a pot: wrap the pot and move it to a sheltered spot.

Diseases and pests

• Green shoots: Variegated forms sometimes produce all-green branches that grow faster. Cut them out at once.
• Branch dieback: Sometimes one or more branches suddenly wither. Cut them back to healthy wood and disinfect your secateurs.
• Scale insects: Brown bumps and sticky leaves. Brush them off or cut out the affected shoots.
• Frost damage: Brown leaves after a cold, windy winter. Wait until spring and then cut out the dead parts.

Through the year

• March: Give compost or organic fertiliser.
• April: Plant. Prune or trim the hedge.
• May: Plant. Prune. Remove green shoots.
• June: Water young plants in dry weather.
• August: Take semi-ripe cuttings.
• September: Plant. Take cuttings.
• October: Plant. Flowering: fragrant silvery-white flowers.
• November: Flowers and scent in the garden.
• December: Protect young plants in hard frost.

Edible and useful

Berries (April–May)

On the widely planted hedging elaeagnus (Elaeagnus × ebbingei), the small, oblong, silver-speckled berries ripen in April and May, when there is little other fruit about. Pick them when they are deep red and soft: then they taste sweet-sour; unripe they are astringent. Eat them fresh and spit out the stone, or cook them into a purée or jam. Other species, such as autumn olive, only ripen in September–October.

Storing

Fresh berries keep for a few days in the fridge. Purée and jam can be frozen or kept in clean, hot jars.

Caution: Only pick fully ripe, red berries. Be sure of the shrub: the red berries of honeysuckle, spindle and skimmia, among others, are poisonous. You can recognise elaeagnus by the silvery scales on the underside of the leaves and on the berries.

Eating and using is at your own risk: see the terms of use.

Recipes

• Spring jam of elaeagnus and rhubarb (Jam · ± 3 jars · 45 min)
• Elaeagnus compote with vanilla (Compote · ± 400 ml (2 small jars) · 35 min)
• Elaeagnus fruit leather (Dried · ± 10 strips · 30 min + 6–8 hrs drying)

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Its roots live together with bacteria that fix nitrogen from the air, much as in the pea family.
• It is one of the parents of Elaeagnus × ebbingei, a widely used evergreen hedging plant.
• The genus name comes from the Greek word for olive; its Dutch name, olijfwilg, means ‘olive willow’.