(Tropaeolum tuberosum) Among Andean tubers, Mashua, a relative of the garden nasturtium is one of the highest yielding, easiest to grow, and most resistant to cold, to USDA Zone 7 or maybe colder. It also repels many insects, nematodes, and other pathogens, thus making it a valuable plant to intercrop with other species. The tubers about the size of small potatoes have shapes ranging from conical to carrot like. Mashua is high yielding, even under conditions of almost no management. You will receive 1 tuber in a one quart pot.