Using hot springs water to irrigate water convoluvus makes it grow to great size without being overripe. The sponge gourds are plump and firm, and they won't go dark when cooked. The whites of the water oats are really white, and the greens truly green with absolutely no black bit at the core.
用溫泉澆灌出的空心菜莖大味美，真的是「粗枝大葉」，但一點也不老；溫泉絲瓜肥厚結實，煮了不會變黑；茭白筍也是白的白，綠的綠，絕不「黑心」。