pale blueberry leaves

[Susa]

I planted some blueberries that looked healthy, but are now growing pale green leaves. Also, a few other leaves are pale but I see the leaf veins are still dark green. What does this mean? I planted them in 50% peat moss and 50% native sandy soil. They are mulched with pine needles and I've been fertilizing with an azalea feed. Should I have done something differently?
Thanks

[rainbowgardener]

Just found this after reading your other post on pale tomato leaves. What you are describing is the chlorosis I was talking about. I would check your soil pH. The azalea feed should be acidifying, but if they are planted in the ground and your soil is naturally alkaline, it is very difficult to change that with amendments. I know, because that's the situation I am in. The acidifying amendments just get neutralized out over time by the surrounding soil. You can add iron with things like Ironite. If you give them some Ironite and they green up nicely, that will at least show you what the problem is.

[JONA878]

Would also add that it can be a sign of Magnesium deficiancy. A spray of Epsom Salts can do no harm and it will knock one more possabilty off the list.