Seed Saving: Tomatoes There are a couple ways to do this. Seed Saving Instructions: Cross-pollination between modern tomato varieties seldom occurs, except in potato leaf varieties which should be separated by the length of the garden. Do not save seeds from double fruits or from the first fruits of large fruited varieties. Pick at least one fruit from each of several plants. Squeeze seeds and juice into a strainer and wash, spread on a paper plate and dry. I ferment my tomato seeds as it gets rid of the gel that surrounds the tomato seed which is where viruses will lurk. I Squeeze the tomato pulp and seed into a glass jar, add water and stir well. Then let it sit and stir once a day for 3-4 days. The surface will get a white mold growing on it (this is a good thing, honest)and the bad stuff will float to the top and the good viable seeds will sink to the bottom. At the 3rd day, take the stuff off the top and toss in your garbage and then rinse the viable seeds again with fresh water and then drain and spread on a paper plate to dry. This really cuts down on any potential viruses. tenzicut