My wizards on my other account are just getting xp and no drops, Then the XP stop and now the plants are just harvesting with no xp no drops nothing, I stop harvesting and soon stop gardening. I can understand on one account this happening but now on my second account also.
I would check and see if your xp bar is registering xp. Take a screenshot of your gardening xp bar, in garden mode then the next time you harvest take another and see if the xp goes up.
This morning I harvested several purple grapes and got drops and XP, after several plants the drops stop and was just getting XP. So I stop harvesting. I had about 20+ purple grapes and now in third day trying to harvest cause the drops and XP are not right. Yesterday I went to my second account and it is doing the same thing, When plant is ready to harvest you might get a drop or you might not. I have planted my last garden for a while. I have never had this happen in my time playing Wizards, Gardening has always been fun and good up till a few weeks ago.
All my wizards have plants needing Harvesting but if they harvest they will most likely not get anything as drops or maybe XP. So I let the plants sit there needing Harvesting. I have cleaned out Pack, sold treasure cards, I even sold seeds to make room for new seeds when they are drop, but still I have same problem. No drops and at times no XP.