Yeah 16 seems a bit much. Martha used a much smaller amount and got great results. If you could boost a plants immune system then it seems like it would do better all around. Maybe help with rust resistance in daylilies that are normally very susceptible. I do have a few and I might do a little experimenting my self. My yard is very hot and humid so I figure if a daylily is going to get rust it will get it here first!