Crowberry

Photo: Maseltov — CC BY-SA 3.0 de · source

Survives zone 2 through 6

Harvest calendar

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

The hermaphrodite crowberry — the arctic-alpine counterpart of common crowberry, and the reason it fruits where nothing pollinates reliably: each flower carries both sexes, so a single plant sets a crop. Black berries about 7.5mm, watery and mildly acid, much improved by frost and long a staple of Arctic diets.

Hardiness

Zone 2–6

Habit

Groundcover

Edible part

Fruit

Ripens

September

Mature size

Prostrate evergreen mat 0.3 m high spreading to 0.5 m or more

Light

Full sun to light woodland shade

Soil pH

4.0–6.5 — acid soils, and tolerant of very acid peat

Environment

Boreal

Native range

Circumpolar arctic and alpine — Iceland, Fennoscandia and the Alps through northern Russia to Alaska, Canada and Greenland, on moors, mountain tops and the drier parts of blanket bog.

Status

Wild

Years to fruit

3–5 yrs

Growth speed

3–8 cm/year — very slow, spreading outward as a creeping mat rather than upward.

Spacing

60 cm (24 in) apart — about 2.8 per m² (2.6 per 10 sq ft)

Leaf shape

Tiny needle-like evergreen leaves 3–6 mm long, arranged closely along wiry prostrate stems with their margins rolled right under — heather-like, and an adaptation to wind and cold rather than drought.

Root system

Shallow, fine and wide-creeping, with the prostrate stems rooting as they run to build a dense evergreen mat; heavily dependent on mycorrhizal partners in the peaty acid ground it grows on.

Fruit description

Round black berries 5–8 mm across, much like black crowberry's — watery and mildly resinous, seedy, and best cooked or blended; they persist frozen on the plant through winter.

Propagation

Layering happens naturally where stems touch the ground, so rooted pieces can simply be lifted and separated. Semi-ripe cuttings root under mist; seed is slow and needs cold stratification.

Pollination

Hermaphrodite — this tetraploid carries bisexual flowers, unlike the dioecious diploid black crowberry, which is the trait the name records and the practical reason a single plant can fruit where black crowberry cannot. Insect- and wind-pollinated. (Bisexual flowers are well documented; explicit self-compatibility trials are not, so treat a lone plant as likely but not guaranteed to crop.)

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.