In Florida where sago palms have been plagued by a difficult to cure scale infestation, university studies have shown that mulching with spent coffee grounds is more effective at eliminating the scale than pesticides. I do not remember if it was Florida State or University of Florida that performed the studies. As I recall, the initial discovery was accidental. They visited a commercial cycad nursery and noticed there was no scale and the only cultural difference from other cycad nurseries was that the owner of this one was using spent coffee grounds as a mulch around his plants.
