there is not much explanations on the bottle and I wrote to the company who didn't answer. So I welcome very well your answer George ! I live in SC near the Atlantic so we are among the lucky ones who have had a great deal of warm temperatures already.
I have them on a shelving outside so plenty of light and sheltered from the hot noon sun. I just think they need a little bit of help so I will try your 1 tsp/gallon. Will let you know, thank you George.