I have a newly transplanted Yucca Rostrata (about 2 months ago) It is 4 feet tall, and planted in a large pot (50 inches round). The soil is made up of fairly organic material, not much sand. We watered it when we planted, and very little since. The soil is dry. I can not remember how they were when I bought the plant, but the lower 2/3rds of the leaves tips are brown, I don't think they were this brown though. The brown is about 2 inches long starting at the tip. There are also a few small cacti around the base that have a white fuzzy growth. Those my gardener sprayed these with insectaside (but none got in the soil). Do I need to water it more? or is it sick? or is the soil wrong? Any help would be great. Thanks