these are my first blueberry plants. no idea what they need. i read ammonium sulfate will help. but at this point, i think they are too young for much of anything.
do they look like they need anything at this time?
Those look healthy and are growing very well. They're not too young to be pushed to maintain that rapid growth. But you do need to be very careful at this stage to avoid salt burn. They can bear next year if handled properly.
Plants take up a lot of water from the soil when they leaf out, so you might find that you have to water them more often in the spring, and also in the summer, when they are bearing fruit. The reddish leaves will likely turn green in about a month.
They could be given a weak solution of Ammonium Sulfate or another soluble fertilizer like Jack's Classic Acid Special,which has most micro nutrients and AS.This should be beneficial if they are going to stay in containers. Brady