Black Spanish round radish
Raphanus sativus niger
 
50-70 days. This winter radish is slower to mature than most regular radishes. Plant them in the fall and harvest as needed. They have a great zippy flavor, a bit hotter than most. Large greens. In mild climates, they are traditionally grow over winter like Asian radishes. Can also be planted early in the spring. Attractive black skin with pure white flesh. Very good keeper.
 
Details:
Plant life cycle: Hardy annual
Site: full sun
Days to maturity:50-70days
Sow depth: 1" 
Plant spacing: 2"
Row spacing: 24"
Approx seeds per packet: 1/16 oz
 
Phytoactive Nutrients
Spanish black radish is known for its unusually high levels of a phytonutrient called glucosinolate that makes it useful as a healing food, particularly for healthy digestion and liver and gallbladder support. Spanish black radish contains four times the amount of glucosinolates found in other common cruciferous vegetables, making it especially impactful to health and disease prevention.3 Interestingly, glucosinolates are responsible for the distinctive scent of cruciferous vegetables, including radishes.
With so many potential benefits, Spanish black radish can be an important instrument in any practitioner’s toolbox. Practitioners may consider using Spanish black radish for:
Gallbladder drainage
Liver support
Detoxification support
As a dietary or food-based supplemental source of indole-3-carbinol
 
Other nutritions
Calcium • CholineMagnesium • PhosphorusManganese • Pantothenic acidBiotin • Vitamin B6Zinc
 
How to grow:
Radishes are cool season crops best planted in the spring and fall. While a French breakfast radish—the rosy scarlet radish with the white tip—comes to maturity in less than 25 days after planting, the black Spanish radish takes twice to three times as long to reach maturity. That means the black Spanish radishes planted back in September are now coming to harvest.