The most cold tolerant food crops we can grow here are things like kale, spinach, collards, arugula, mustard greens, mache (corn salad), and many herbs such as cilantro, dill, sorrel, and chives. Certain lettuces are very cold hardy, but they cannot take the frost quite as well as the plants mentioned above--good cold hardy varieties include the French heirlooms, “Reines des Glaces” and “Merveiles des Quatres Saisons.” These most tender and delicate looking lettuces can take quite a beating when it comes to cold weather.