Botanical Name: Raphanus sativus
Days to Maturity: 60–70 days
Hardiness: Frost-tolerant annual
Variety Information: 3"–4" diameter, black skin with white interior. 'Round Black Spanish' is a medium-spicy radish.
Type: Winter radish (Learn more)
Attributes: Good for Containers
When to Sow Outside: RECOMMENDED. 8 to 10 weeks before your average first fall frost date. Optimal soil temperature is 65°–85°F. Successive Sowings: Every 10 days for about 3 weeks. In Mild Climates, successive sowings can be continued until temperatures are too cold (below 60°F) for germination.
When to Start Inside: Not recommended.
Days to Emerge: 5–10 days
Seed Depth: ½"
Seed Spacing: A group of 2 seeds every 5"
Row Spacing: 12"
Thinning: When 1" tall, thin to 1 every 5"
Harvesting: Harvest at any size— tiny for hors d'oeuvres or large for cooking, but before the ground freezes (unless well mulched).