As far as adeniums are concerned, I find that the less attention I lavish upon them, the better they fare. Some water here and there, Florida rain whenever it falls, MiracleGro when I think about it and leftover orchid bloom boster solution when I think about it and a good drench of BT when caterpillars appear and we're in business. Grow, my pretties, and don't even think of rotting on me! It sounds awful, but whenever I tried anything else, they declined noticeably. I also have an army of little lizards that continually patrol the branches in search of little insects. I think they help a bit.
Take care, all.
Sylvain.
