I had read of a UFL study on this a while back but can't find that reference now. All I can locate is that "research does not support it" or no research has been done." However, Tom Broome, who is acknowledged by the pros as the cycad guru swears by it. I've had success myself keeping the cycad scale at bay and whether it is the coffee grounds or just plain good luck, either way, it can't hurt.
http://www.cycad.org/documents...
http://jacksonville.com/entert...
