Fire Candle Radish Seeds. 30-40 Days to maturity. Annual, open-pollinated, and non-GMO seeds. Raphanus sativus. Looking more similar to a red carrot than spring radish, the Fire Radish candle is an Italian heirloom and one of the most unique and vibrant radishes available. Long and narrow like a Daikon rather than a scrimp, rounded variety. Fire Candle radish matures at about 8-9 long in 30-40 days and can be sown nearly any time of year, but tastes best and sweetest in cooler growing seasons such as early spring and late autumn. Spring radish is a cool season crop best sown direct in early spring-late summer. Like many root vegetables, radish does not transplant well and should be direct sown. Plant 2-3 seeds in. deep, 3-4 in. apart in very loose, organic, and well-drained soil in full sun. Seeds germinate in 4-7 days, thin back to 4-6 inches apart once true leaves establish. Harvest as roots show 1-2 in. diameter above soil. Radish will bolt to seed in summer heat. About 2,675 seeds per ounce.