My tomato seedlings are 5-7 days old. The stems and some the veins on the leaves have turned purple. I have been googling like crazy to find out what happened. From what I have read the consensus seems to be that tomato seedlings are not able to absorb phosphorus from the soil when the temperatures are too cool, so they develop a phosphorus deficiency. The day before yesterday it was pretty cold outside and I didn't turn on the heat in my house the entire day or that night either so I am thinking that is what did them in. Maybe?
Anyhow, I am keeping my house warm now. What else should I do? Should I fertilize them (very diluted of course) with fish emulsions or bone meal? Or do I just leave them alone and hope they recover? I especially would like to hear from anybody that has had this issue and if you did have this issue, what did you do about it and how did your plants turn out?