What is the soil you're growing them in? Have you done a soil test? Have you added any organic matter or fertilizer? It looks pretty barren. I don't even see any weeds.

Here's some more photos of my setup.

another photo

last one

Im tempted to get another tomato plant and grow it in store bought soil in a pot just for comparison.

Has it been hot? I notice that my plants will do that when they get beaten up by several days in a row of hot sunny weather. It's their way of reacting to stress and protecting themselves. They are stressing, but still look ok colorwise.

I am definitely no expert, but I'm guessing your soil composition is to blame. I know you said that you threw in some peat moss and compost, but adding sand to clay will usually leave you with a soil composition kind of like concrete. It makes it difficult for plant roots to penetrate through the soil, and water tends to run off instead of absorb into the soil.

If it were me, I think I would first loosen up the soil a bit around the plants and then add in more organic matter to help improve soil structure.

It can't hurt -- and depending on your current weather, it could be a distinct advantage -- to mulch those plants. You can mulch with almost anything, including shredded office paper, but something that will add organic matter to the soil quicker would be an advantage (as compared with bark or wood chips). Grass clippings, perhaps: unless the grass has been treated with something to kill weeds (and I have no idea if anything in lawn treatment besides broad-leaf weed killer would be bad for the veggies). And in addition, mulch helps prevent disease organisms from splashing onto the leaves during rainfall.

The first photo seems to show roots at ground level. The plant should have been planted much deeper (to keep the roots cooler; to help keep soil moisture more consistent; also to allow additional roots to grow along the stem). Lacking mulch, and depending on your weather (zone 9 makes me think it's hot), the roots (already stressed by planting) may be hotter than they're happy with.

I'm also worried about water -- not where the wet area is, but on the opposite side of the plant. Is that soil moist or dry?
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If I understand correctly, you have tomatoes planted all along the one side of the standing wire fence, three-deep. The holes in the fencing probably aren't large enough that you can put your hands through, so how will you reach the tomato plants that aren't at the front of the bed? (For maintenance, removal of hornworms, examination of spotty leaves -- not to mention harvest of large fruit in one piece!)
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What variety are you growing? Depending what the variety is, those ring cages are most likely grossly inadequate. Even if the variety is a short one, the wire gauge may not be heavy enough to support a fruit-heavy plant without bending over (ask me how I know -- and mine was a 4' and cherry-fruited plant which had lost most of its bulk to severe pruning to control Late Blight).

Ok lots of good ideas here I'll try to do these things in the next couple days... On the temperature, the temp range for this week is from a low of 50 degrees to a high of 80 degrees, the previous weeks were more or less the same so if anything it's been too cold for them. The only thing weather wise that is notable is It was very windy for a few days.
That wire fence thing and those metal sheets on the ground are shelves I bought for cheap from the local borders bookstore when it went out of business. There's a lot of cats in the neighborhood and that's my overkill way of keeping them away from the plants. that and I'm trying to kill the crab grass surrounding the thing. I can open and close the wire fence like a door.
There is 3 tomato plants, one each of better boy, early girl, and a sungold. Id get a brandywine as ive heard good things but i dont think i have the room.
Anyhow I'll replant them deeper in the ground (should I go so far as to bury the bottom branches a little?) and put potting mix around them and start mulching them with either straw or wood chips. And ill start watering them by hand as well so the dirt gets more evenly wet.

**respectful moment of silence in memory of Border's**

As I understand it, wind increases evaporation. It will have stressed the plants.

A unique hinged cat-guard! Amazing.

should I go so far as to bury the bottom branches a little?

I've grown a lot of tomatoes, but I'm not an expert and I really don't know whether it would be better to re-plant the tomatoes lower or leave them and just mound up soil around them. You planted them a couple of weeks ago and they don't seem to have done much ... maybe wait to see if you get other opinions on that.

In any case, I don't think you have branches yet; I think those are compound leaves (the actual branch will grow in the angle where the petiole of the compound leaf -- what you're calling the branch -- attaches to the main stem). Above all, you don't want disease organisms from the soil to get onto the leaves, so if you bury the plants lower, it would be a good idea to remove the lowest leaves which touch the soil.

Unfortunately, Better Boy will get 8' tall, Early Girl about 7-8', and Sun Gold is reportedly a monster which will grow much larger. [Depends on weather, soil, and other conditions.] You'll see a lot of threads which discuss ways to support large plants which have been started in dinky cages.