Is It Normal For Blueberry Sprouts From (Lower Body / Lower Stem) To Roots Turn Red? Is It A Disease, Or Is It Caused By Stress Or
is it caused by something else? I don't have a pH meter so I tried using rockwool media and made it sour with regular vinegar.
Certified GKH Gardening Expert
Vinegar should be used very carefully, and with a pH meter. This is especially true since it is toxic to plants. Citric acid is a much better alternative. Seedlings nor young rooting cuttings can handle acetic acid so vinegar is not to be used in this situation.
In your situation, and not having a pH meter, it will be best to start these in soilless media that is already pH balanced, and DOES NOT contain nutrients. Nitrates of any kind should NOT be used on blueberries.
What you are seeing is stress from toxicity, and probably low pH. I would transplant these into a seedling starting, or inert soilless blend as soon as possible. Do not feed until it is showing new top growth. Then feed it with something made for blueberries, since you do not have a meter to adjust the pH properly.
This article will help you to care for blueberries: https://www.gardeningknowhow.com/edible/fruits/blueberries/growing-blueberry.htm
This article will help you to propagate cuttings from them: https://www.gardeningknowhow.com/edible/fruits/blueberries/how-to-propagate-blueberry-bushes.htm