Have to laugh, FL is mostly sand. Drainage is the most important issue. Soil that stays too wet encourages disease. Thats why I direct the sprinkler heads away from the Amaryllis beds. I tried something new this spring. I planted my 12 new bulbs in a 22 inch pot, with good potting soil, instead of in the ground. Experiment to see if the bulbs are healthier. Also I can move the pot to get the optimal sun conditions.