I bought an elephant ear bulb with a short stalk coming out of it 3-4 weeks ago. I planted it in a large planter. While the stalk has recently turned dark green, it has not grown vertically at all yet. Last night, I put a plastic cover over the planter due to cold temps. I took the cover off today and the stalk was brown and limp! Help! How do I save my bulb and jumpstart the growth of this elephant ear? I have read that others have seen stalks and leaves within 4 weeks. Also, the instructions say to plant the bulb 4" under the soil line. I planted it so that the stalk tip was peeking through the soil, about 2-3" below soil line. Is this wrong? How do I save my bulb and get it growing? Thanks!