I personally dont like foliar feeding my plant's. the leafs dont burn but get this dryed up spots all over them, and i belive it couses glogging so they cant "breath" normally. I also do like Zandor, just raise the humidity a little but not until the plant are abought 1 meter high and are starting to move water and nutrients so high they could need a little help. I'm not saying foliar feeding is bad .. just not for me