All it takes is the soil to be water saturated for a few days and your plants are dead. The roots need to breath, thats why the grow books stress soil with good drainage. I advise multiple locations of a few plants each not just for safety reasons but also to learn from experience how plants grow in specific locations. Gardeners often plant in the spring in a built up mound to prevent spring water saturation, then as the season gets hotter and dryer the roots spread down. Happy growing