Because I mix my own seed soil mix and container soil mix, I often get volunteers in my starts. With tomatoes, I sow the seeds in a specific pattern in a community pot, so any tomato that sprouts outside of the pattern is deemed a volunteer. Most of the time, seeds of same variety sown in the same container will germinate within days of each other so that's another indication.
This spring, I managed to mix up a bad soil mix AND sow the Wild Boar tomato seeds in it. I can't say for sure whether it was my mix or that these seeds seem to be slower to germinate than average. One of the "BAD" in the mix was that when I tried to water, the soil turned hydrophobic, all the water beaded on the surface, then soaked all at once into the soil. This made some of the seeds float up and drain into the gap between the soil and the container.
When the tomatoes came up from along the container edge, and there was no recognizable pattern in the sprouts, I knew I was in trouble.
I ended up saving most of the sprouts and separating them. Now that they're starting to fruit, 4 of them have turned out to be Principe Borghesi, and 2 of them are looking like they might be the Wild Boar tomatoes. Trouble is that the label for the community pot ALSO became
invisible BEFORE I had the chance to separate the plants, so I'm still waiting to see WHICH Wild Boar tomatoes.
I am saving a few of them that is if the volunteer melons don't strangle them out first. 
I hope the melons are cantaloupes not pumpkin, I threw a bunch of pumpkins in the compost last year as well. I love eating the seeds so there are a ton of their remains in there.
). I'm interested as well to see what I get since the parent plants were all hybrids. Since they were both beef-steaks, it'll be funny to see if I don't get cherry toms 
Is there any way to tell what squash or cucumber I am growing in a row by volunteer? I have gardened for awhile but as there are only the first few leaves, all I can see is that it is a squash, pumpkin or cuke. 
