We started our tomato plants off in the conservatory and about six weeks ago and then moved them to the greenhouse at the start of April. They were looking beautifully green and healthy last week. But at the weekend I noticed that they had started going yellow. The bottom leaves are getting worse but the top growth is still lovely and green. What is wrong with them?
I have consulted the books, looked it up online, read a few blogs and still I am not sure. I have been letting them dry out before watering so I don’t think it is over or under watering. I bought some Epsom Salts and used as a foliar spray and added a bit to the pots too, so I don’t think it is a magnesium deficiency.
Could it be a virus? It has been rather cold this week and we have a broken window in the greenhouse, would they do this if they got a bit chilly at night?
We feel sad that out little seedlings are sick and I just don’t know what to do to help them. It would be so dissappointing to start again. Can anyone offer some advice?