In your situation I would be checking soil pH immediately. That the blueberry shrubs held their leaves and made it through the season is a good sign. There are ways to lower soil pH quickly, using a solution of tap water and vinegar. But you really need to know the soil pH before attempting this.

Can high ph levels cause this kind of coloration?

High pH symptoms are only going to be readily apparent on new growth. You didn't get new growth probably mostly because you didn't fertilize. I think the discoloration you are seeing is just normal for this time of year especially up north.

If we knew where you live it would help.

Next year fertilize regularly with 21-0-0 if your pH is above 5 and urea if below 4.5. Either that or get some other fertilizer for acid loving plants like slow release Osmocote.

If soil pH is down around 4.5, a blueberry transplanted in the spring will double in size over the course of the summer. It is not advised to apply fertilizer when the shrub is set out in the spring, because too much leaf growth too soon will over tax the root system leading to dead leaves. Those of us who grow blueberry shrubs in southern Wisconsin, southern Minnesota, Illinois, Indiana, and Ohio are obliged to check soil pH and take appropriate measures if we want to be successful. The only way around this is to grow the shrubs in a pot, in a soil mixture that is known to have correct pH.

I live just south of the Quad Cities in Illinois, so yes I am up north a ways. Would the best time to adjust the ph be now, or should I wait until spring to start that?

Now would be a good time to test the soil and see where you are at. Sulfur can be applied anytime but will only be activated by bacteria during warmer weather.

I've never had dead leaves from the tops growing too fast. Anytime the tops are growing rapidly so are the roots. They will stay in balance and the leaves have no reason to die. If it gets too dry or if the plants are fertilized incorrectly then there can be leaf die back. I've never see it otherwise.

Now would be a good time to add some elemental sulfur for that plant next year. I find it takes a couple years for the stuff to break down completely. For a quicker fix, I use a powder called Copperas, which is really iron sulfide. At this time of year, I wouldn't worry about it. Ammonium sufate is another additive high in nitrogen, which acidifies as well. I quit fertizing completely after July. New, tender growth late in the season is susceptible to winter kill. I think I'd extend that mulch much further around that bush as well. Blueberries have a shallow, fibrous root system that does not compete well with other plants. I also think a soil high in organic matter is more important maybe than anything else.

Thanks for the replies guys. I'll go ahead and get started with adding some garden sulfur. The Espoma brand on amazon looks pretty good I think. First I'll have to get a ph tester though.

@brookw

I think I agree, we need to mulch farther out around the plant. I think once the grass dies for the season, that'll be on the list. Thank you for the suggestion.