Re: blueberry bushes off color
It makes a difference if the leaves are actually red, or if they are more "red-brown." If they are red like mine are early in the leaf year, it is usually a sign of cold weather. They'll green when it warms up although it's been warm already so............ If the leaves are red-brown, is probably magnesium deficiency from the soil, either because the soil is cold, the pH is too high or low (More then likely)or because magnesium is lacking. If you've checked your pH and the condition continues, you can try fertilizing with epsom salt dissolved in water. With blueberries, you have to keep checking pH unless you live in a area with acidic soil. If the pH is above 6.5 the bush wont do well. If they are yellowing then its pretty much the same issue except with an Iron deficiency. Again probably related to soil pH.
Blueberries are super easy to grow if you maintain a low pH to the soil. At this point I think you need to test the soil that you've treated and see where it is. It's a good idea to test the soil every couple years if you're not in an acidic area.