Purchase seeds from a reputable nursery or online. Watermelon radish seeds may be hard to find, but you’ll have no problem ordering from from an online seeds catalog.
Like radishes, watermelon radishes are just as easy to grow and very similar in planting and growing methods.
Plant anywhere from early to late spring, and give them about 65 days to mature.
You can plant every 2 weeks for a continuous harvest.
Plant seeds in well drained, fertile soil.
Soil must be sandy and rich in organic matter.
Before planting watermelon radish seeds, amend the soil with 2-4 inches of well composted organic matter and 2-4 cups of all purpose fertilizer (16-16-8 or 10-10-10) per 100 square feet. Work these into the top 6 inches of the soil.
Once soil temperatures have reached 40F (4C), you can sow the seeds directly into the ground.
Sow seeds in rich soil evenly spaced in rows 6 inches apart at a depth of 1/2 inch.
Tamp the soil down lightly and water the seeds in.
Once seedlings are 2 inches tall, thin them to 2 inches apart.