Only the strong survive

For the last week or two I have been trying to improve the growing conditions in my living room "greenhouse". My tomatoes have developed edema with varying degrees of severity. For some of the tomatoes, like Chalks Early Jewel or Gold Medal, it has caused slight wilting or dropping of leaves, but the plants are still doing well. For others, like Gold Rush, it completely wiped out ALL my transplants. I feel really happy that I over planted on accident, so now even with the loss of some of my transplants, I can still have plenty left over.

So, what is edema?

University of Minnesota Extension has an excellent article on this topic. In short:

"Oedema, often spelled 'edema', is a physiological disorder that develops when a plant absorbs water faster than it can be lost normally from leaf surfaces. The term itself means 'swelling', which describes its initial stages. Excess moisture builds up in the plant and causes swellings that appear initially as pale-green or water-soaked blisters or bumps, primarily on the undersides of leaves. Although oedema mars the beauty of plants it rarely kills them."

Here are pictures of my effected tomatoes:

I ended up scrapping 5 tomatoes today because they were dropping all of their leaves. The leaves were coming off whole branches at a time, like in the pictures. If I looked closely at the stems, there were tiny cankers on them as well. I am trying to find a watering situation that will help improve this situation and I have also set up a small fan to help with air flow around the plants. Ideally, I would be able to give them all some more space so they weren't so crowded, but I just don't have any where else to put them! If they can just make it a few more weeks it will be warm enough to get them outside, and then I think this problem will take care of itself.