Iwai Daikon Radish Seeds | Yamato Yasai Heritage Variety | Japanese New Year Radish | Heirloom | 50 Days

Iwai Daikon Radish Seeds – Yamato Yasai Heritage Variety | Japan’s Celebrated New Year Radish

Iwai Daikon is a rare and cherished traditional Japanese radish carrying the distinguished Yamato Yasai designation — officially recognized as a heritage vegetable of Nara Prefecture, Japan. Unique for its slender, elegant form, Iwai Daikon produces a long, slender white root of approximately 1 inch diameter at the base, crowned by a clump of lush bright green leaves. Its refined size, tender texture, and cultural significance have made it a centerpiece of Japanese New Year’s (Oshogatsu) celebrations for generations. Ready in approximately 50 days. Open-pollinated heirloom, non-GMO. Approximately 21,000 seeds per pound.

Variety Details

• Botanical Name: Raphanus sativus (Japanese daikon type)
• Designation: Yamato Yasai — officially recognized heritage vegetable of Nara Prefecture, Japan
• Type: Heirloom, open-pollinated, non-GMO
• Root: Long, slender white root; approximately 1 inch diameter; mild, tender flesh
• Greens: Lush, bright green leaves — edible; excellent in soups and stir-fries
• Flavor: Mild, sweet, tender — less pungent than large daikon varieties
• Days to maturity: ~50 days
• Seeds per pound: ~21,000
• Season: Cool season — late summer to early fall planting
• Sun: Full sun
• Soil: Loose, deep, well-drained — at least 12 inches deep for straight root development

Cultural Significance

Iwai Daikon is one of the most culturally meaningful vegetables in Japanese heritage gardening. The Yamato Yasai designation (大和野菜) is awarded by Nara Prefecture to vegetables with documented historical cultivation in the region, protecting traditional cultivars that reflect Japan’s agricultural heritage. Iwai Daikon is a traditional centerpiece of Oshogatsu (Japanese New Year) cuisine and continues to be celebrated by heritage gardeners and Japanese culinary enthusiasts worldwide.

Culinary Uses

• Oden: The most classic Japanese preparation — thick-cut daikon simmered for hours in dashi broth until completely tender and deeply flavored; a winter hot pot staple
• Buri daikon: Simmered with yellowtail (buri) in a soy-mirin broth; a traditional New Year’s dish throughout Japan
• Daikon oroshi: Finely grated as a fresh condiment alongside grilled fish, tempura, soba, and yakitori; Iwai’s mild sweetness makes it ideal for this use
• Tsukemono (Japanese pickles): Sliced or julienned and quick-pickled in rice vinegar, salt, and sugar; also used in nukazuke (rice bran pickle) for a deeply fermented result
• Raw in salads — thinly sliced or julienned for a fresh, mild crunch in green salads and sunomono (vinegar-dressed Japanese salads)
• Miso soup — sliced and simmered with tofu, wakame, and dashi; absorbs flavor beautifully
• Korean kimchi-style preparations — cubed or julienned kkakdugi (radish kimchi)
• Edible greens: Young leaves are edible — stir-fry with sesame oil and garlic or add to miso soup

Planting Guide

• Sowing: Direct sow in late summer to early fall for a cool-season harvest. Do not transplant — daikon develops a deep taproot and does not tolerate root disturbance.
• Depth: Sow seeds ½ inch deep, 1 inch apart. Thin to 3–4 inches apart once established.
• Soil preparation: Work soil deeply — at least 12 inches — in loose, well-draining, stone-free ground. Compacted soil causes forked or misshapen roots.
• Watering: Consistent, even moisture throughout the season. Irregular watering causes cracking and pithy texture.
• Sun: Full sun for best root development.

Harvesting

• Harvest when roots reach desired size — Iwai Daikon is best enjoyed young and slender, approximately 50 days from sowing.
• Shoulders will be visible above the soil surface when roots are ready. Gently loosen soil around the base before pulling to avoid breaking the slender root.
• Greens can be harvested at any stage and used as a vegetable in their own right.
• Roots store well in the refrigerator for 2–3 weeks; keep greens attached and wrap in damp paper towel.