My guess is that this condition will resolve in 30 to 60 days. As to the cause, it could be that the roots are not fully operational, and some nutrient, possibly magnesium, is not being taken up and distributed to the leaves. Blueberry shrubs depend on fungal associations, aka mycorrhizal fungi, to enhance the process of absorbing minerals in the soil. When the shrub is transplanted, the roots are disturbed, and the system stops working. Fungi are everywhere, and they will get established once more, in due time.

ericwi, I would love for you to be right. Thanks :)

ericwi, I did some further reading, and it seems that blueberries have a specific family of fungus, Ericoid Mycorrhizae that they partner with. I guess I have no way to know if my soil is innoculated with these specific fungi... have you ever tried adding it? If so you can reply on the other thread I just opened on GW on the subject.

http://forums2.gardenweb.com/forums/load/fruit/msg061753236174.html

This is my third year with blueberries, one thing that I tried this year for the first time was adding white vinegar to my tap water before watering, my plants have never looked better.

It is true that blueberries live in symbiosis with a specific group of fungi that are called ericoid. However, I do not think that these fungi are hard to find, unless you live in the Sahara. When conditions are right, meaning moisture, food source, and pH level, then the appropriate fungus will take root and multiply.

ericwi, I love your responses! "Buy nothing, do nothing" :) Easy enough!

mhayes8655, I also have recently started adding a small amount of vinegar to my tap water prior to watering. However, I have read that the acidifying effect is temporary- the vinegar binds up bicarbonates into organic molecules, lowering the pH, but then microbes consume the organic molecules, re-releasing the bicarbonates and re-raising the pH. In order to get sustained lowering of pH, it seems you must keep reapplying vinegar or use a different acidifier. So I don't think it hurts, but it's not permanent.

I use it every time I water. 4 tbsp in a 2 gallon watering can. Its cheap and I don't mind the extra work. Been applying sulpher a few times a year also. Would like to try ammonium sulphate but haven't been able to find it locally.

ericwi, you were exactly right! I watered the soil down to a pH of 5.5 using sulfuric acid and simply waited. After only a week of waiting, the reddish foliage is greening right up. Must have been some nutrient issue, and the roots are now in action to correct it. Kudos and thanks!

Thanks for posting the outcome. I'm glad your blueberries are looking good. There are several plants with red pigment, several varieties of seaweed, and also several shrubs that show up with red bark in the winter, when the leaves have fallen. So red pigment is associated with colder temperatures. I suspect that there is an alternate method of photosynthesis going on, and that the plant is using sunlight to make sugar. It might not be as efficient as chlorophyll, but it might be the only method available when the temperature drops.