I have blueberry bushes that are now over 7 feet tall. How low can I prune them?
I have 600 blueberry bushes that range from 6 to 15 feet tall. I am getting ready to cut them all back to about 5 feet. Will that harm them in any way and is it ok to do that at this time of year?
Severe pruning will not kill the plant and normally results in bigger but fewer berries. The best time to prune is when the plants are dormant, which is late fall through very early spring. This article will help: https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-plant-pruning.htm
I have an abundance of composted leaves (mixed) mostly pin oak. Is this good for my blueberries?
Yes, composted leaves are very good for all plants. It will help add nutrients back to the soil.
Blueberries like acidic soil. Use pine needles.
When is the best time to prune blueberry bushes, and how much do you cut off?
My blueberry bushes put off little amounts of berries. They are over three years old. What makes the veins turn green, then yellow. The bed is made up of compost, pine needles, and oak leaves. It receives sun then shade.
Iron deficiency is normally the cause of that. Here is more information on that problem and how to fix it: https://www.gardeningknowhow.com/plant-problems/environmental/leaf-chlorosis-and-iron.htm
What kind of fertilizer do I need to buy for my blueberry bushes? They have been planted for three years and have not produced many berries. Read that they need acid soil, how do I get this?
These articles will help you with that:
Moved into present location 1 1/2 years ago. It has two very old blueberry bushes. They are very bushy and one is about 8-10 feet tall. I have pruned out the old stuff. They have some new canes, very tall. Can I cut the very tall older canes and the newer canes that have buds on them back to 5-6 feet tall without killing the plant? I would like to also get some berries this year if possible.
You can cut back the plant, but I would not do so all at once. Every year, cut back no more than 1/3 of the oldest canes, until you have got the plant back to a manageable size. Here is more information on pruning blueberries: