You mean when the tomatoes fall to the ground and rot, or the seeds? I don't think I have a chance of volunteers because I never leave tomatoes on the ground for fear they will start disease or cause bugs to try to eat it and their arrival will cause disease. Also don't see how seeds could come up the next year because I don't usually grow tomatoes in the same spot. Although I am sure a few seeds make it to the compost.
I know I have volunteer sunflower, amaranth, and even watermelon seeds sprouting up all over the place. Because we would never throw watermelon seeds in the trash, but in the compost. And the amaranth and sunflower came up because the roommate, needing something to do, forgot I told him not to put weeds in the compost or turn the amaranth and sunflower seeds into the soil when he tilled. Although they are easy to just pull up, it takes much time and bending over to get all the volunteers out of the garden.
You can see some of the amaranth growing with my beets here.
I don't know whether amaranth competes with the beets for nutrients, or the roots choke out other plants, or adds beneficial nutrients to the soil, so I pull them when they are growing close to my edibles when they are big enough to grab easily with bare fingers. I usually just sit on the ground, on the nice cushioned straw to pull weeds and volunteers. Otherwise I am unsteady on my feet when bending over.
