About Black Spanish Round Radish: This 16th century European favorite, actually a large winter radish, can be traced far back into European history; this is one of the most ancient varieties of radish available. As well as being valued for its rather sharp flavor, it had various medical benefits. Black Spanish radishes certainly would have been found in the colonial gardens of early America.
Black Spanish Round Radish Germination: Since Black Spanish are winter radishes, they should be planted about two months before the first expected fall frost. Plant them in very rich, deeply worked up soil about 1/2" deep and 1" apart; later, thin the seedlings 4-6" apart. Black Spanish radishes do not tolerate heat well.
Growing Black Spanish Round Radish Seeds: Radishes do well with consistently moist soil and the addition of organic matter such as compost. Do not allow the soil to dry out, but also avoid overwatering as this can cause splitting.
Harvesting Black Spanish Round Radish: Black Spanish radishes have the best taste when harvested at 3-4" in diameter. They have a strong, hot flavor and store well for winter use.
Saving Black Spanish Round Radish Seeds: Radishes will cross pollinate with all other varieties of radish, and must be isolated by at least half a mile from other varieties to protect genetic purity. Allow the radish plant to fully mature and send up a flowering stalk; the pods will form and turn from green to brown. Pick the brown pods and allow them to dry for several days. Thresh out the seeds by opening the pods by hand, or by applying pressure to crush them. Store the seeds in a cool, dry place for up to five years.
Detailed Black Spanish Round Radish Info: Raphanus sativus. Biennial. 60 days. 2,500 seeds per oz. 6-12" height. 2-3" spacing. Produces 3-4" black skinned, round radishes with white flesh.