Want to grow a cool weather vegetable that will bring color, crunch and variety to your plate? Try growing watermelon radish – an enticing root vegetable that serves as a welcome change from the usual varieties of cool season crops such as beets and greens.
Watermelon radishes are an heirloom variety of Daikon radish originating in China and are a part of the Brassica (mustard) family. Their smooth, pale green skin hides a beautiful rose-red or magenta center, which give it its unique and playful name. And no, this radish does not taste like watermelon — it simply bears a resemblance.
Late fall through early spring is an ideal time to plant watermelon radish by seed or transplant. Be sure to use well-drained, fertile soil, adding 2 inches to 4 inches of compost and mixing it into the existing soil.
Sow the radish seeds directly into the ground when soil temperatures are as low as 40 degrees Fahrenheit, although seeds will germinate best at 55-75 degrees Fahrenheit. Stop sowing once temperatures reach 80 degrees Fahrenheit.
Seeds should be evenly spaced 1 inch apart at a depth of half an inch, in rows 6 inches apart. Lightly press the soil, and water the seeds regularly.
When the seedlings are an inch tall, thin them to 3 inches apart so that the radish root (the tasty part that is eaten) can form. It is recommended to plant them every two weeks in milder climates so that you have plenty of radishes to harvest for a longer period; otherwise, planting successively twice in the spring is best.
Radishes need a minimum of six hours of sun per day to produce adequate bulbs, which can grow to be as large as a baseball. As you sow, consider practicing “companion planting” to help your radishes thrive. Beets, peas, carrots and leaf lettuces are “companion plants” that are mutually beneficial, along with strong-smelling herbs such as nasturtium and allium family species such as onion. Take note that radishes typically do not thrive when planted next to potatoes.
Watermelon radishes can be harvested in approximately 60-65 days — slightly longer than other radish varieties. Some people prefer to harvest them when they are the size of a baseball. When harvesting, look for radishes with noticeably pink taproots for an extra pink interior. Keep in mind that the larger the bulb, the more mellow in flavor and woodier it will be. For a spicy, peppery flavor and tender crunch, consider harvesting when the bulb is golf ball-sized or two to three inches in diameter.
Once harvested, these radishes do not need to be peeled before eating. They can be eaten raw, pickled or cooked (although they lose some of their color when cooked). They are most popular sliced thinly and added to fresh salads and grain bowls or roasted with tangy vinegar sauces. They also provide an excellent source of fiber, Vitamin C and A, and minerals, especially when consumed raw. Store bulbs in the refrigerator without their leafy tops, and they will remain fresh for several weeks.
If you’re not a fan of the spicy bite of a raw radish, roasting helps to mellow their edge.
Here is a simple way to prepare roasted radishes:
Roasted Watermelon Radishes
6-8 medium watermelon radishes (about the size of golf balls)
Salt & pepper
Fresh herbs for garnish
Preheat oven to 425 degrees. Wash and dry the radishes, then trim off the roots and tops. Slice in half and toss with 1 tablespoon of olive oil. Arrange cut-side down on an unlined sheet pan. Sprinkle with sea salt and fresh cracked pepper. Roast until slightly golden brown for about 40-50 minutes, checking every 20 minutes. Garnish with chopped fresh herbs such as thyme, Mexican mint marigold or parsley.