riverbank grape

Photo: Bill Summers. USDA SCS. 1991. Southern wetland flora: Field office guide to plant species. South National Technical Center, Fort Worth. Courtesy of USDA NRCS Wetland Science Institute. — Public domain · source

Survives zone 2 through 8

Harvest calendar

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

One of the most cold-hardy grape species on Earth — some vines survive to about -57°C (-71°F) — and thanks to that hardiness plus resistance to phylloxera and powdery mildew, it has been the key rootstock and breeding parent behind cold-climate hybrid wine grapes such as Frontenac, Marechal Foch and Baco Noir. ⚠ Know the look-alike: across eastern and central North America, moonseed (Menispermum canadense) twines alongside wild grapes, carries similar dark hanging clusters, and is potentially fatal. Three checks — a grape has 2–4 rounded, pear-shaped seeds while moonseed has ONE flat crescent seed; a grape climbs by forked tendrils and moonseed has none; a grape's leaves are toothed and moonseed's are not. Open a berry and look at the seed before eating any wild grape.

Spread warning. Naturalized and locally classed as invasive in parts of Italy (e.g. Abruzzo, Lombardia, Marche, Piemonte, Toscana), having escaped from rootstock plantings introduced to fight phylloxera

Hardiness

Zone 2–8

Habit

Vine

Edible part

Fruit

Ripens

Sept–Oct

Mature size

Very vigorous vine 10–20 m, occasionally to 25 m

Light

Full sun — climbs to the canopy top to reach light

Soil pH

6.0–7.0

Environment

Riparian

Native range

Central and eastern Canada and the northern-to-central US, from Quebec to Texas and eastern Montana to Nova Scotia, chiefly along riverbanks and bottomlands

Status

Rootstock

Years to fruit

3–4 yrs

Growth speed

Fast, to about 15 m; matures in 3–4 years

Spacing

200 cm (79 in) apart — about 4 m² (43 sq ft) per plant

Leaf shape

Alternate, broadly heart-shaped, 8–20 cm across, usually three-lobed with coarse pointed teeth, bright green and smooth or lightly hairy on the veins beneath.

Root system

Shallow, and deliberately so -- a riverbank species that tolerates wetter ground than most grapes and roots near the surface rather than deep. Worth knowing because it is the opposite of the genus stereotype: as a rootstock it confers lower vigour and earlier ripening, where V. rupestris confers deep roots and high vigour.

Fruit description

Small juicy berries 6–12 mm across, purple-black with a bloom, tart until softened and sweetened by frost

Propagation

Seed (fresh-sown, or 6 weeks cold stratification if stored), hardwood cuttings taken December/January (15–30 cm lengths, or short single-bud sections with bark stripped to encourage rooting)

Pollination

⚠ DIOECIOUS — needs male + female (a vigorous fruitless wild vine is usually a lone male)

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.