Ok, I planted two lantana bushes a little over a week ago here in Dallas. I watered deeply twice a week. Perhaps that was too much. They both now have black spots on their leaves and are not doing overly well. The one that gets the most sun is doing a bit better than the other one. Have I overwatered? If so, how can I correct this? Will they come back if I just stop watering and let them dry out some? How often should they be watered? Thanks.