I have a cherry tomato plant. I would like to take the seeds to plant more of them. Do I have to do termot and maasrot on the seeds or the cherry tomatoes I bring in the house to use for seeds? What if I don’t bring them in the house but put the seeds straight into a container to sprout outside?
If the plant is generally for eating, and not especially for seeds, there is an obligation to separate terumos and maasros from the tomatoes, even if you intent to use these particular tomatoes for their seeds alone (see Shulchan Aruch. Yoreh De’ah 331:13).
If the plant is in the yard and you don’t bring the tomatoes into your home, but rather pluck a small number. one at a time, they are not obligated in separating terumos and maasros (see Rambam, Laws of Maaser, Chap. 4).