You misunderstood, Cheryl. I am sure I simply did a bad job giving advice about spider mites on plumeria. I meant to tell Mark that IF he could find no evidence of spider mites (he posted photos of leaf damage) he might want to use the Mg solution. I use that solution to green up my plumeria and orchids. It has nothing to do with mite treatment though. I spray the leaves of my plumeria once and sometimes twice a day with plain water from a hose, early AM and/or late PM. This deters spider mites since these pests seem to prefer dry conditions.
