Rosaceae

blackthorn / sloe

Prunus spinosa

blackthorn / sloe

Photo: Unknown — CC BY-SA 3.0 · source

2
3
4
5
6
7
8
9

Survives zone 4 through 8

Harvest calendar

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Best planted in early spring after your last frost, or in fall before the ground freezes, depending on your climate.

⚠ The sloe is intensely astringent and essentially inedible raw off the bush, but once the first frosts soften its tannins it is traditionally used to make sloe gin, jellies, and preserves — kernels are cyanogenic like other Prunus stones.

Spread warning. Locally naturalized outside its native range in parts of eastern North America (New England, Pacific Northwest) and Tasmania, though not documented as a major ecological threat in those areas.

Hardiness
Zone 4–8
Habit
Shrub
Edible part
Fruit
Ripens
After first frost (Oct–Nov)
Mature size
Suckering thorny shrub 2–5 m, thicket-forming — the classic hedging blackthorn
Light
Full sun to partial (hedgerow) — reduced sloe crop in shade
Soil pH
6.0–7.0 (near-neutral)
Environment
Temperate
Native range
Native to Europe, western Asia, and parts of northwest Africa.
Status
Both wild and cultivated
Years to fruit
3–4 yrs
Growth speed
Moderate — roughly 30–45 cm/year
Spacing
300 cm (118 in) apart — about 9 m² (97 sq ft) per plant
Leaf shape
Small oval to obovate leaves 2–4.5 cm long with finely toothed margins, dull dark green.
Root system
Shallow-rooted with vigorous, spreading lateral roots that readily produce suckers.
Fruit description
Small globose drupe (the sloe), 10–12 mm across, black with a distinctive waxy blue-purple bloom, with thin flesh tightly adherent to the stone.
Propagation
Seed has deep dormancy and needs 2–3 months (sometimes up to 18 months) of cold stratification; more reliably propagated by separating root suckers, layering, or half-ripe cuttings taken in midsummer.
Pollination
Self-fertile

The edible parts listed above are a starting point, not a field guide. Identify a plant with certainty — ideally against a local authority — before eating any part of it, and read the full disclaimer. Spotted something wrong? Report it.

Growing guide

Fertilizing. Tolerant of poor soils and thrives on chalk or limestone; excessive lime can cause chlorosis, and little supplemental feeding is needed beyond that.

How it spreads. Strongly suckering — spreads via shallow lateral roots to form dense, thorny thickets, a habit historically exploited for stock-proof hedging.

Growing tips. Very shallow-rooted and tolerant of poor, dry, and calcareous soils, so it is often used for wildlife hedging. Flowers very early, often before the leaves emerge, so blossom can be damaged by late frost, though heavy fruit set usually still follows.

Grow journal

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About the data

Zone figures are typical published ranges — microclimate, drainage and siting shift them by a zone in either direction. Store links are found by an automated search, refreshed every six weeks. Availability is seasonal; stock and prices are not tracked.

Venlo — a reference for cold-hardy edible plants