It’s mid September and sadly most of the container-grown tomato plants on my rooftop are on their last lap. A few green stragglers remain and the vines are starting to yellow and fade. Thankfully I’ve got another crop still running over at my community garden plot where the plants aren’t subjected to the intense sun and heat that causes the roof plants to hit such an accelerated pace. When the plants were producing at full stride, I was so caught up in enjoying (and photographing) the harvest I completely forgot to save some seeds for next year’s crop.
Of course, it’s not too late. I’ve outlined my process for seed-saving tomato seeds below. The process with very wet fruit like tomatoes is a bit different than with a relatively dry fruit like peppers. While peppers are as simple as scooping out the seeds and setting them to dry, tomatoes call for a slightly more complex method. You can, in theory use the pepper method with tomatoes. However, you may have noticed that tomatoes have a gelatinous layer surrounding each seed. This layer is called a germination inhibitor and is made up of a chemical that prevents the tomato seeds from germinating inside the fruit. While the scoop and dry method will remove that layer, fermenting the seeds first will also serve to kill diseases your plant may have contracted along the way.
Fermenting Tomato Seeds
1. Choose a heathly tomato from a healthy plant – While you’d rather save the best-looking tomatoes for eating, sick fruit from sick plants pass on… well, sickness. And remember, you can always scoop out the seeds for saving and eat the rest.
2. Scoop the insides out of your tomato (seeds and all) into a plastic yoghurt container. A lid isn’t critical but it helps with the smell.
3. Label your container with the variety name and set it somwhere warm but out of direct sun. You can prop the lid on but don’t seal it shut. Remember you’re fermenting here so this is going to stink. Find an out-of-the-way spot if you can.
4. Stir your container once or twice a day until a “nice” layer of white mold forms on top. This usually takes a few days. Don’t leave the fermented goo sitting for too long after this stage or your seeds will start to germinate in the container.
5. Your seeds are now ready to harvest. Thankfully you do not have to dig around in this mess in order to fish them out. All of the good seeds will have sunk to the bottom with all the useless stuff left floating in the mold. Separating the good from the bad is as easy as scooping or pouring off the moldy layer from the liquid. Remove as much as you can without losing any of the good seeds.
6. Fill the container with water, stir, and repeat step five. Repeat refilling with water and scooping until all the bad debris has been removed.
7. Rinse off the remaining seeds in a strainer and spread them out onto a pad of newspaper.
8. Set the seeds out to dry for a few days. Don’t forget to label them if you’ve got more than one variety on the go. Take it from me. I always think I’ll remember what I’ve got but I NEVER do.
9. Package your dried seeds, label, and store for next year.
More photos can be seen on pages 167-168 of You Grow Girl. All photos by Gayla Trail.