Rosaceae

Japanese strawberry

Fragaria iinumae

Japanese strawberry

Photo: Alpsdake — CC BY-SA 4.0 · source

2
3
4
5
6
7
8
9

Survives zone 3 through 7

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.

A diploid, hermaphroditic wild strawberry from the mountains of Japan and southern Sakhalin; along with woodland strawberry, it's one of the two diploid ancestral species behind the cultivated garden strawberry, and genetically the earliest-diverging lineage among the diploid Fragaria species.

Hardiness
Zone 3–7
Habit
Groundcover
Edible part
Fruit
Ripens
Summer–autumn
Mature size
Low rosette 5–15 cm, spreading by runners
Light
Full sun to partial
Soil pH
6.0–7.0 (near-neutral)
Environment
Temperate
Native range
Northern and central Japan (Hokkaido, Honshu) and southern Sakhalin, Russia, in alpine/subalpine zones from roughly 200 to 2,500 m depending on latitude.
Status
Wild
Years to fruit
2–4 yrs
Growth speed
Seedlings grow slowly at first, then the growth rate increases.
Spacing
30 cm (12 in) apart — about 11 per m² (10 per 10 sq ft)
Leaf shape
Trifoliate, the leaflets thin-textured, bluish-green and rounded at the tip, distinctly smaller than in the cultivated strawberry.
Root system
Shallow and fibrous from a short woody crown, almost all of it in the top 15–30 cm, with new roots striking down wherever a runner touches soil. Nothing to dig around: the crown must sit at soil level, buried too deep it rots and planted too high it dries out.
Fruit description
Small pale pink to whitish berry under 1 cm, soft and mild. Of interest less for eating than for breeding: this diploid is one of the ancestral genomes of the cultivated octoploid strawberry.
Propagation
By seed, sown in early spring under glass (four or more weeks to germinate), or by division of runners, ideally July–August; unlike the octoploid garden strawberry, seed-grown offspring come true to the parent's characteristics.
Pollination
Hermaphrodite and insect-pollinated; unlike most polyploid wild Fragaria, which tend toward separate male and female plants, diploid species including this one are self-fertile hermaphrodites.

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. Prefers fertile, well-drained, moisture-retentive soil in sun to part shade (fruiting decreases in shade); adapts to light, medium and heavy soils across mildly acid to basic pH, with a mulch of pine or spruce leaves.

How it spreads. A runner-spreading perennial reaching about 0.3 m, forming colonies in moist, sunny alpine and subalpine sites.

Growing tips. One of only two diploid ancestral species behind the cultivated garden strawberry, and genetically the earliest-diverging lineage among the diploid Fragaria — valued in breeding for cold tolerance. Needs cool, moist conditions echoing its alpine habitat; young leaves are edible cooked as a potherb.

Grow journal

Sign in to keep a dated log of when you planted, bloomed and harvested this plant.

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