Farkleberry

Photo: Eric Hunt — CC BY-SA 4.0 · source

Survives zone 6 through 9

Harvest calendar

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

Also called sparkleberry — the largest-growing, most tree-like Vaccinium here, and unusually tolerant of alkaline, calcareous ground where the rest of the genus struggles. Grown mostly for showy flowers, exfoliating bark and fall colour rather than the bland (if historically pie-worthy) berries.

Hardiness

Zone 6–9

Habit

Tree

Edible part

Fruit

Ripens

Sept–Oct, persisting into winter

Mature size

2.4–4.6 m (8–15 ft) tall, 1.2–3 m (4–10 ft) wide

Light

Full sun to part shade

Soil pH

5.0–7.5 (acid to mildly alkaline) — unusually tolerant of calcareous soil for the genus

Environment

Temperate to subtropical

Native range

Southeastern United States — Virginia south to Florida, west to Texas, north to Kansas.

Status

Wild

Years to fruit

3–5 yrs

Growth speed

Medium

Spacing

300 cm (118 in) apart — about 9 m² (97 sq ft) per plant

Leaf shape

Alternate, elliptic to obovate, 2–5 cm long, thick, leathery and glossy dark green, with entire or barely toothed margins — semi-evergreen in the south of its range, colouring red before dropping further north.

Root system

Deep for the genus and the reason it matters: sparkleberry is the one Vaccinium here with a substantial taproot, which is why it tolerates drier, less acid soil than any other blueberry and is used as a rootstock to give cultivated blueberries a deeper root system.

Fruit description

Black, bland-flavoured, historically used in jellies and pies

Propagation

Seed after about three months' cold stratification is the usual route and gives the taproot the species is valued for; softwood and semi-ripe cuttings root but slowly and less reliably than most Vaccinium. Seedlings are also raised deliberately as rootstock for cultivated blueberries on soils too dry or too alkaline for them.

Pollination

The flowers hold their pollen in tubes that open by pores at the tip, so it is shaken out by bees that vibrate the anthers — bumblebees and solitary bees do this, honeybees largely cannot. Cross-pollination gives a markedly better set than selfing — the same greenhouse trials that measured V. darrowii found fruit set higher after crossing in V. arboreum too. Plant two.

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.