Osaka Purple Mustard is a striking Japanese cultivar of Brassica juncea that transforms a humble salad green into edible art. Dark green-purple leaves threaded with bright white veins mature in just 20 to 29 days, making it one of the fastest crops you can grow. Whether you harvest tender 4 to 6 inch leaves for salads or allow them to reach full size for cooking greens, this variety brings both visual drama and authentic Japanese heat to your kitchen, it's even one of the primary ingredients in making wasabi. Hardy from zones 4 through 10 and thriving in full sun, Osaka Purple is equally at home as a spring crop, a fall succession, or grown indoors as a colorful microgreen.
Photo © True Leaf Market
Growing Conditions
USDA Zone
4-10
Sunlight
Full Sun
Water
Moderate
Soil
Well-drained, Fertile Loam
Preferred Temp60-75°F
Growth Stats
—
Height
—
Width
6 in
Spacing
20–29
Days to Harvest
PeriodAnnual, Perennial
TypeForb/herb
Plant Profile
Sunlight
Full Sun
Water
Moderate
Zones
4-10
Size
?in H x ?in W
Growth
Annual, Perennial
Care
Moderate
Hover over chart points for details
Highlights
What sets Osaka Purple apart is the stunning interplay of its deep purple-tinged foliage with those luminous white veins, a visual statement in any garden or salad bowl. The speed is remarkable: ready to harvest in as little as three weeks, it's perfect for impatient gardeners or those wanting quick succession plantings. Beyond beauty, this is a genuinely flavorful mustard with a pronounced bite and strong character that reflects its Japanese heritage and role in wasabi production. You can harvest it young for delicate salad leaves or push it to maturity for robust cooking greens, giving you flexibility few other mustards offer.
Common Uses
This mustard shines brightest in the kitchen when harvested young as tender salad leaves, where the leaves' crisp texture and peppery bite add complexity to mixed greens. At full maturity, the larger leaves excel in boiling preparations and traditional cooked green dishes where their robust flavor stands up to heat and other strong seasonings. Beyond fresh salads, Osaka Purple is prized as a microgreen, the young seedlings deliver concentrated flavor and striking color to garnish plates, grain bowls, and Asian noodle dishes. Its pedigree in wasabi production hints at its compatibility with Japanese cuisine and spice-forward flavor profiles.
Growing Timeline
First Bloom
Mid-spring
First Harvest
Early Spring
Last Harvest
Late Summer
Care Instructions
Direct Sow
Sow Osaka Purple seeds directly into the garden or containers in spring as soon as soil is workable, or in late summer for a fall crop into early winter. Press seeds lightly into moist soil and keep the bed consistently damp until seedlings emerge, typically within 5 to 7 days. For succession planting, sow new seeds every two to three weeks to ensure a continuous supply of tender leaves.
Harvesting
Osaka Purple offers flexibility in harvest timing. At 20 to 29 days, you can begin harvesting individual outer leaves when they reach 4 to 6 inches long for a tender salad experience, or wait for the whole plant to mature into larger cooking greens. The distinctive white veins against purple-green foliage make it easy to judge readiness, harvest leaves that have fully developed their color contrast and crisp texture. For microgreen harvest, cut plants at soil level when the first true leaves have emerged, typically around 10 to 14 days.
Growing Calendar
Enter your ZIP code to see a personalized growing calendar for this plant.
Companion Planting
Ecology & Traits
Edible
Scientific Classification
Brassica juncea (L.) Czern.
Family
Brassicaceae
Genus
Brassica
Duration
Annual, Perennial
Native Status
L48 (I)AK (I)HI (I)PR (I)VI (I)CAN (I)