We get volunteers every year in our compost pit, in the vegetable plot even after tilling, and below the pre-compost rotating barrel. I didn't find them worthwhile to cultivate compared with seed I start myself. They were unimpressive. On the other hand, acorn squash volunteers grown from seed dumped in the compost have been real winners. Go figure. The only way IMO you will be able to decide is to save a few of the apparently strongest ones and see what happens. Personal experience can be the best teacher.

To answer your original question, "What's wrong with my tomato plants?": It is most definitely sun scald, which someone else also pointed out. Take them out of the direct sun a little to let them recover and make sure to just give as much water as they need. Over-watering them after they've already been burnt might be their death knell. To address some of what was said here after that: Based on your pictures, the plants are slightly leggy, but only slightly in my opinion - the real issue you are dealing with now is that you put your plants into too much direct sunlight too quickly, and they need to recover from that before they'll do anything. I have seen some people who choose to grow seedlings on the windowsill without lights and they can turn out OK - not great - but hey, it's cheaper and if it works for you, no need to change it... everyone on here has their own opinions though. I choose to grow under lights and I sprout a month earlier than some and grow in the cooler conditions in my basement. That works great for me, but that has one primary disadvantage - the plants take a little longer to harden off to wind and direct sunlight... But hey, I'm willing to accept that cost since they are generally good stocky plants with good root systems. If you should choose to start indoors and grow under lights (which is recommended), you don't need to spend a fortune on lighting systems. I grow the majority of my seedlings under a jerry-rigged lighting fixture I got at a yard sale coupled with a florescent bulb I picked up from a local hardware store. No matter what you choose to do going forward, definitely check out the link that Dave provided. While growing tomatoes is far from rocket science, there are still some basics worth knowing before getting started. If you don't choose to follow everything you read, that's fine, but at least you'll have more to work with than before.

Its called blossom drop. Check the FAQ's at the top of the page or do a search at the bottom. You will find a wealth of info on it. Its normal with high or low temps ...

The 2015 season was a different one for me this year. This is the 6th year I've grown tomatoes in my little backyard here in Tulsa. The first 4 years, I only grew in containers. For the 2014 season, I built two 4' X 10' raised beds, and also had a couple of containers. But I switched from 18 gal. plastic containers to 20 gal. Smart Pots. My strategy from my first year was to mostly grow one plant of 12-15 different varieties to try as many different ones as I could. 2015 was different for me in a couple of ways. First, I started growing from seed. And second, I decided to grow tomatoes that I already knew I liked, and to grow 2 plants each. I started seeds for Brandy Boy, Big Beef, Black Cherry, Yellow 1884 Pinkheart, Jaune Flamme, Break O'Day, and what I thought was Sun Sugar, and Super Sweet 100. Those last 2 ended up not being true to seed. I was bummed about this, as Sun Sugar is my favorite. Whatever seed I got that was supposed to be Sun Sugar was a small red cherry instead. It was decent, but not Sun Sugar. Whatever was supposed to be Super Sweet 100 seed, was instead a golf ball size red that was mealy and bland all season. I started my seeds on Feb. 14, and they did fantastic. I moved them out to my "temporary" greenhouse (8' x 8') around March 10. By the time I planted on April 8, most of my plants were 18-24" tall and thriving. I planted a little early for Tulsa. It helps being a Meteorologist and knowing what the likely weather will be for the next couple of weeks. ;-) My plants were thriving until the rains came......and came.....and came some more. We didn't have it as bad as Dawn did down south, but we still had way too much. I started getting the first ripening fruit on a few of them the week before Memorial Day. Jaune Flamme, Break O'Day and Yellow 1884 were the first to ripen. The other varieties started ripening the next week. All of the fruit that ripened before June 6th or so were very watery. We had that dry spell during the first couple of weeks of June, and that helped a lot. I also tried a little experiment with my cherries this year. I said I had 2 plants of all of my varieties, so I decided to do one of each cherry in the raised bed and one in a Smart Pot to see if there was a difference in taste. I can report that there was not a significant difference in taste for Black Cherry, not-Sun Sugar, and not-Super Sweet 100. They all tasted the same whether from the Smart pot or the bed. The only difference in the cherries was the Black Cherry in the Smart Pot succumbed to Gray Mold about 3 weeks quicker than the one in the raised bed. Like I'm sure most of you experienced, the disease pressure was much higher this year than normal, due to the heavy rain. I normally get Gray Mold on any of the Blacks I've tried. And I usually eventually get Early Blight to some degree on all the others. It was quite a bit faster this year. And to top it all off, around July 4th, my neighbor behind me decided to use Round Up all over his backyard to kill his bermuda and do some landscaping. My tomato plants did not like this one bit. They all died within a week. I was pretty mad at first, but luckily, they were mostly played out by then. So the loses weren't too bad. I didn't have too many fruit left. It would have been a different story if it was June 4, instead. I guess that's the risk you take when you garden in the middle of town. BRANDY BOY - This one was my only new variety. These did well overall, but I probably will not grow again. I know this sounds crazy, but I'm just not a huge fan of the Brandywine taste. Call me crazy, I know. I grew a Brandywine back in 2012 in a container and they all tasted watery and bland to me. And it got Early Blight quicker than others that year. On a whim, I decided to try Brandy Boy this year in the bed. Both plants produced about 20 good-sized beefsteaks. I still just wasn't crazy about the taste. If you like Brandywine, these may be worth a try. Definitely had better disease resistance than Brandywine, at least in my case. BIG BEEF - These did great for me, and I plan to always grow this one. The taste isn't "knock your socks off", but it's very good for a hybrid. And they produce like crazy. This was my second year growing it. Every year, each plant has pumped out at least 35 fruit. Most were in the 8-16 oz. range. And for what it's worth, these 2 plants were the last to die from the Round Up accident. BREAK O'DAY - This variety is probably my favorite pink. There's something about the "zing" in the flavor that my wife and I both really like. I've grown this one all 6 years and will continue. It's a little bit smaller plant (4'), but it pumps out the tomatoes. I've always had at least 30 from every plant. In 2012, I got over 60 from one plant before it finally gave out. BLACK CHERRY - Another staple that I've grown every year. I love this cherry tomato. Not much to say about this one. It's a very popular tomato, and it always lives up to its reputation for me. The only negative about these is they are susceptible to Gray Mold, typical for Black Tomatoes. I had hundreds of fruit from each plant before they died. Both plants were huge, as usual. YELLOW 1884 PINKHEART - This is a creation from The Tomatoman here in Tulsa, and I think it is only available through The Tomatoman's Daughter. It's another tomato that I grow every year. It typically produces 8-16 oz. yellow beefsteaks with pink in the middle when fully ripe. This is my favorite beefsteak. It's flavor is hard to describe, maybe creamy-sweet, almost buttery. I know it sounds weird, but it is oh so good. Every person I've given one to has commented on how good it tastes. The first few this year were watery, but after that, they were fantastic. I got about 25 from each plant. I had 2 huge fruit this year, too, which was new. One was 21.9 oz. and another was 20.7. Lisa (the Tomatoman's Daughter) said she'd never heard of ones that big. JAUNE FLAMME - This one is an orange, golf ball size tomato that is very juicy, sweet and tangy. I've grown this one every year. When I grew them in containers, they had quite a bit of blossom end rot. I haven't had that problem in the raised beds. These are early and very productive. I lost count on these this year, but I think each plant produced at least 75. I'm not going to go into the not-Sun Sugar and not-Super Sweet 100. I took a chance and ordered the not-Sun Sugar seed from Amazon. That was a mistake that I will not make again. The not-Super Sweet 100 seed actually came from Burpee. They emailed me about a month ago saying there was a mistake in their production of Super Sweet 100 seeds this year, and offered to send me new seeds early next year. I'll give those another try, but will likely not order from them again. I've got a Black Cherry, 4th of July OP, Jaune Flamme, Green Zebra, Break O'Day, Yellow 1884 PH, and Johnny Joe's going in the garden for Fall. I planted out on July 10. I've already had a couple ripen, and have several fruit growing on all of them. I had worms really bad on these in late July. I sprayed a couple of rounds of Bt, and haven't seen any since. Hopefully I'll get some good production before our first freeze. So overall, it was a decent year. It wasn't my best year for sure, but I guess it could have been worse. The rain was too much and lead to more disease than normal. And the Round Up incident lead to a premature end to my season. But I grew from seed for the first time this year, and successfully, I might add. So I'm going to say this season was a success. I look forward to seeing other reports, too. Lee