300+ Watermelon Radish *Heirloom* NON-GMO | ORGANIC | FRESH GARDEN SEEDS. Shipped with USPS First Class Package. Watermelon Radish Garden Root Vegetable Also known as Rooseheart and Red Meat, this unique radish is a part of the Daikon family. It is very popular in Asian cuisine as it originates from south east Asia. It can be served hot or cold in stir-fry dishes and salads.Spacing - 4 inchesDepth - 1-inch deepLike other radishes, Watermelon Radish is a cool season crop. The root vegetable is usually ready to harvest by early to mid-spring. if left in the ground longer it can grow larger--from the average size of a golf ball to the extraordinary size of a grape fruit.