1/2 tsp (teaspoon) per gallon doesn't sound bad at all. Any chance they could be over watered....wet feet? They don't look great, but don't look horrible either. Hopefully the weather will turn soon, and maybe let them dry out a bit. If it makes you feel better stop the fertilizer.

I just got back from a trip to the garden center and your plant looks like the seedlings on offer right now. They have spent a little bit too much time in the smallish pots and should have been planted by now...our weather here in N. CA. has been unusually cold and rainy for this time of year. Your plant should be alright if you don't over water and fertilize. When you plant give it some really good amendments...

Thanks for the insight guys. I will try to keep them going for another week and hopefully it warms up.

I don't THINK I have been overwatering. They aren't showing any other symptoms, just this very poor color. I wait until the soil has dried and the pots are light. If anything, I feel as though I underwater them. But I suppose that some could be over watered since I water all of them at the same time. So some could still be wet while others are dry. I probably won't water them again this week.

I've planted a lot sadder looking tomato plants than yours and gotten plenty of nice tomatoes! I think they'll do just fine once they are established outside.

That's looking a little like magnesium deficiency to me... happened to my tomatoes once a few years ago. This site says to spray the leaves with an epsom salt solution, but iirc, I added about a tbs of epsom salt to a gallon of water and watered with it just once, then resumed watering with very dilute fertilizer as usual (MG), and it cleared right up.

Over the week, they now look worse. Some of the leaves have completely wilted and died.

My luck is that they are diseased, and since I don't know entirely what it is, I'm now worried about putting them in my soil and possibly contaminating it for years to come. Perhaps this year I just buy a few plants and chunk all these in the garbage. Really disappinting, I was looking forward to these guys...

Zach, when you say that you planted them in "soil" do you mean potting mix or garden soil? If it really was garden soil, it tends to get compacted and can starve the roots of air (which is why it should not be used in pots). You might be able to rescue them by planting them in potting mix, and they will probably revive and be fine by the time they finally get planted in the garden.

Nope, it was bagged potting mix, not garden soil.

ZachS Did they get cold? It's been unseasonably cold and rainy here these past 10 days or so ( I planted them out about 3-4 weeks ago). My planted tomatoes look terrible, light green/yellow and wilted leaves, and I looked around at other gardens ( community garden) most all look the same. I'm going to leave them until it warms up then give them a little liquid fertilizer. They looked fine and were growing well before the weather change. Most tomatoes don't like extremes in temp...the only one doing well is a hybrid, the others are heirlooms and open pollinated types.

Your tomatoes don't look diseased to me but it is your call.

It was cold here all week, freezes every night since Monday and snow in the middle of the week. However, these guys have been indoors their while life, except for a little bit on Saturday and Sunday, which were in the 60's or 70's and sunny (they were kept in the shade). The problem began a couple weeks before that though, before they had spent any time at all outside.

I will have to take some new photos, the leaves have started to form some brownish necrotic spots and others have completely died. That is what made me start thinking disease issues.

Glad to know that they were grown in potting mix, but I don't know what is wrong with your seedlings unless the addition of fertilizer simply put them over the top.

This is a shame... I know the feeling.

Thank you all for your help and trying to figure this out. After going through them, I think I can slavage enough of them to grow a few of them, though I am cutting about 2/3 of the tomatoes I had planned on planting this year.

Might end up that our summer this year won'tmake for a very good tomato season anyhow, so maybe it's a good thing.

They will probably still be waiting for planting for another week again, supposed to get as low as 39º and thats up in town. Its usually several degrees colder here at the house...

Over fertilising can actually lead to nutrient deficiencies as imbalances cause various elements to become 'locked-up'...which looks to be the case here with a possible manganese deficiency. Generally, tomatoes don't really need much fertiliser until they start to set fruit. In our shortish growing season in the UK, we don't transplant outside intil late May/early June...and seedlings can start to look a bit ratty, tbh...but usually grow away as soon as they are in warm outdoor loam.