I planted the sweet potato in a humongous pot and it seems to be doing great thus far. My gardening pal, Juliana, told me that she had planted hers on the ground and it took over her garden. No matter what the books say, I trust someone who has already grown the same under the same soil and weather conditions best. I left the original two store-bought sweet potatoes half-way buried in a pot with soil and they are still sending new 'slips' (green growth), so I am saving those to plant later. How generous of them!