Italian buckthorn (alaternus) Rhamnus alaternus
Italian buckthorn (alaternus) (Rhamnus alaternus) is an evergreen perennial shrub in the Rhamnaceae family, native to Mediterranean basin. It grows 2–5 m (6.6–16 ft) tall and 2–4 m (6.6–13 ft) wide, wants full sun and low water, and is hardy to about -12 °C (10 °F). Space plants about 2 m (6.6 ft) apart.
Plan Italian buckthorn (alaternus) in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Italian buckthorn (alaternus) at a glance
| Type | Perennial shrub, evergreen |
|---|---|
| Family | Rhamnaceae |
| Mature height | 2–5 m (6.6–16 ft) |
| Mature spread | 2–4 m (6.6–13 ft) |
| Spacing | 2 m (6.6 ft) centre to centre |
| Sun | Full sun, at least 5 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance none |
| Soil pH | 6–8.5 |
| Cold hardiness | About -12 °C (10 °F) once established (roughly USDA zone 8) |
| Heat stress | Likely above about 42 °C (108 °F) |
| Flowering | from about March for 4–7 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | High |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | Mediterranean basin |
| Common in gardens of | 🇪🇸 Spain, 🇮🇹 Italy, 🇫🇷 France, 🇵🇹 Portugal, 🇬🇷 Greece, 🇲🇦 Morocco, 🇬🇧 United Kingdom, 🇳🇿 New Zealand |
| Invasive in | New Zealand (an environmental weed): check local rules before planting |
Is Italian buckthorn (alaternus) toxic?
- People: mildly toxic
- Cats: mildly toxic
- Dogs: mildly toxic
- Parts: berries, bark
Buckthorn berries and bark are strong laxatives; do not eat them.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Italian buckthorn (alaternus)
No well-documented helpful pairing. Group it with plants that like full sun and low water.
Questions about Italian buckthorn (alaternus)
- How far apart should I plant Italian buckthorn (alaternus)?
- About 2 m (6.6 ft) apart, centre to centre. A mature plant spreads 2–4 m (6.6–13 ft).
- Does Italian buckthorn (alaternus) need full sun?
- Full sun: at least 5 hours of direct sun a day.
- How much water does Italian buckthorn (alaternus) need?
- Low water. Drought tolerance is high and waterlogging tolerance none.
- How cold-hardy is Italian buckthorn (alaternus)?
- It tolerates about -12 °C (10 °F) once established, roughly USDA zone 8.
- When does Italian buckthorn (alaternus) flower?
- From about March for 4–7 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Italian buckthorn (alaternus) poisonous to cats and dogs?
- For cats it is mildly toxic; for dogs mildly toxic; for people mildly toxic. Buckthorn berries and bark are strong laxatives; do not eat them.
- What grows well with Italian buckthorn (alaternus)?
- There is no well-documented companion pairing for Italian buckthorn (alaternus). Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade A (A: strong evidence).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- RHS Find a Plant (plant profiles and growing guides), Royal Horticultural Society
- Euro+Med PlantBase, Botanic Garden and Botanical Museum Berlin
Notes and assumptions
- A summer-dry plant: water it through its first summer, then rarely or never; it wants sun, lean soil and sharp drainage, and is killed by summer irrigation and heavy clay more often than by drought.
- A glossy evergreen (‘Argenteovariegata’ is edged cream) with tiny, scented, yellowish flowers loved by early bees, then berries turning red to black. Tough against salt wind and drought; a fire-resistant hedge plant.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
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