The watermelon radish is a delightful Chinese cultivar also known as a beauty heart radish, which mirrors in color a full-size seedless watermelon when cut open. Translated from the Mandarin shinrimei to "beautiful heart inside," it resembles an average, tan-to-green-colored radish on the outside. This heirloom variety of radish, which comes in smaller round and larger oval sizes, is lightly sweet and can be given a wide range of culinary treatments.
Also known as a rose heart or Asian red meat daikon, the watermelon radish is principally harvested in the fall. That does not mean they cannot be harvested at other times of the year in consistently warm climates though. For most settings, however, avid gardeners recommend that this vegetable be planted in the late spring or early summer to receive full sun and at least three months of warm weather that will not dip below 60°F (about 15°C) during the seedlings' earliest stages. At maturity, the round types can reach 4 inches (about 10 cm) in diameter, and the ovals can be 5 inches (about 12.5 cm) long and 3 inches (about 8 cm) wide.
In North China, where the watermelon radish was born several generations ago in Beijing, many cooks treat this root vegetable as a fruit. This could be a simple slicing with a dusting of sugar. It could also entail grating the larger, duller-colored varieties, which lose some vibrancy in color, into a dessert dish like pudding or a cake frosting for a hit of sugary heat. Vendors have even been known to tout these vegetables as being better than the region's prized pears.
This is just one avenue of approach though for a watermelon radish. Westernized chefs are more apt to use this vegetable in savory applications. Raw slices or gratings might be used in a salad or to ornately garnish a full plate of food. Though cooking these radishes can cause the stark coloring and sweetness to fade, it is still acceptable to use them as a substitute for radish in soup or sauteed with garlic and onion. One recipe even slices them thinly and crisps them into chips with a deep-frying in oil or butter and a sprinkling of salt.
One the most obscure of the many radishes in the Roman-born Brassicaceae family, the watermelon radish is likely to be beat to market by other species. Among the most common in the West is the tiny cherry belle radish. In the East, however, it is not unusual to find several types and sizes of daikon in white, green or violet hues.