Cranberry
Vaccinium macrocarpon
Low acid-bog evergreen — happiest mulched alongside blueberries.
- Type
- Fruit · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Red · Pink
- Sunlight
- Full sun to part shade
- Watering
- High
- Soil
- Acidic, moist, free-draining
- Feeding
- An acid-loving plant fertilizer in spring, and no lime at all.
- USDA zones
- 2a–7b
- Frost tolerant
- Yes
- Flowering
- May
- Pruning
- Trim the runners back in early spring.
- Plant out
- at the last spring frost
- First harvest
- 140 days after the last spring frost
- Harvest ends
- 7 days after the first fall frost
- Apr–Jun Bud Break
- Jun–Jul Flowering
- Jul–Sep Fruit Set
- Sep–Dec Harvest
- Jan–Apr Harvest
- Plant spacing
- 11.8 in
- In-row spacing
- 11.8 in
- Between rows
- 17.7 in
- Square-foot density
- Not suited to SFG
- Root system
- Shallow roots, spreading on surface runners
- Working depth
- 4–10 in
- Can reach
- 18 in down where the soil allows
- Spread
- 24 in–3 ft across, about 1–1.5× the width of the plant
- Shallowest pot
- 8 in of soil
The roots themselves stay shallow and near the crown; the spreading is done above ground by runners that root wherever they touch. The colony walks outwards while the parent plants age out, so keep the young rooted runners and replace the old ones every few years.
Wiry runners root as they go across the surface of an acid, permanently damp peat, and the roots themselves are shallow and hairless, feeding through a fungal partner instead. Sand over the top each few years is what keeps a bed productive.
Figures recorded for Cranberry itself. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- When
- September–October, after the berries have colored fully — flavor improves after the first light frosts. Plants (acid, boggy beds) crop from year 2–3.
- What to look for
- Deep uniform red (variety-dependent, some near-maroon), firm, and the classic test: a truly ripe cranberry bounces when dropped on a hard surface — soft non-bouncers are overripe or rotten. Seeds inside turn brown. Sour even when ripe; ripeness is color and firmness, not sweetness.
- How to harvest
- Dry-pick by hand or with a berry comb/scoop, working through the low wiry mats; home growers don't flood-harvest. Pick when the plants are dry.
- How often
- One or two picks in autumn; berries hold on the plant in good condition for weeks, so no rush — but finish before hard freezes and winter wet.
- Storing the crop
- Exceptional keeper for a berry: 1–2 months refrigerated in a sealed bag; a year frozen (freeze raw, no prep). Cook into sauce, juice, or dry them; too tart to eat raw for most.
Blueberries, Lingonberry, Heather
Good neighbors
Ripe cranberries are full of air pockets and bounce — growers actually test them that way.
Green-leaved fruit with red flowers, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com