This is the third year for my blueberries. Last year the leaves were a reddish colour and the plants had very few leaves really. No berries to speak of, but they had only been in a year. I decided that I hadn't given them enough water early on, and I needed to correct that. This year I was all over the water and monitored the blueberries very closely. They seemed to be growing exactly like last year. Very few leaves growing, reddish and just sort of pathetic. It wasn't the water. I read everything I could about red leaves. The consensus seems to be the sun turns them. I was not sure. I loaded a bunch of alpaca manure on them and now about three weeks later, we have the first green leaves I've seen since I put them in about two years ago. Live and learn.