How to Save Tomato Seeds

Some of you may still have the last of your tomatoes inside your house ripening. If you would like to save the seeds or if you don’t have any seeds but would like to learn how to save them for next year then read on. It’s a simple procedure where we must remove the gel from around the seeds before drying them.

But before that, the first thing to consider is if the tomato is a hybrid or an open pollinated (OP) or an heirloom tomato. Don’t save hybrid tomato seeds as they won’t grow out true meaning they will not grow out to be the same tomato. They revert to one parent or the other and are unstable so you won’t know what you’ll get. If you have open pollinated (OP) or heirloom tomatoes you can save the seeds as both will grow out into the same tomato. An exception to this might be if you plant cherry tomatoes close to the tomatoes whose seed you want to save. Cherry tomatoes could cross-pollinate with other tomatoes but most heirloom tomatoes do not cross with each other. Just grow your cherry tomatoes away from  your other ones.

Put tomato seeds in a small jar of water (viewed from the top)

Put tomato seeds in a small jar of water (viewed from the top)

First you want to save a tomato that is really ripe and soft. To save the seeds from tomatoes we must remove the gel from around the seeds. Cut the tomatoes open and squeeze the tomato with the gel and seeds into a jar and add about 2-3 inches of water. Cover the jar.

white mold grows on top of the water

white mold grows on top of the water

In a few days you will notice that there is a white mold growing on top of the water and most of the seeds will have sunk to the bottom of the jar. Don’t freak out, this white stuff is fermentation working on your seeds.

drain the tomatoes and stuff off

drain the tomatoes

After about 4 days, strain the tomato seeds in a fine sieve or strainer and wash the yuck and tomato stuff off of the seeds. If you wait too long the seeds will start to germinate which will ruin them.

Put your seeds on wax or parchment paper. Write down the variety.

Put your seeds on wax or parchment paper. Write down the variety.

The seeds can now be put on wax paper to dry. If you use paper towels, the seeds may stick to the paper causing trouble removing them. Be sure to label them so you remember which variety they are. After they are thoroughly dry, store them in a plastic bag or jar for next year. It’s fun to save seeds and see what happens next year.

How to collect heirloom tomato seeds

Tomato seeds fermenting in a jar. On the plate are some dried seeds.

I don’t collect hybrid tomato seeds as they may not grow back true.What that means is they may revert back to one parent or the other that they were crossed with. Heirloom tomatoes will grow back true.

The only heirloom tomato seeds I collect are from my giant tomatoes as I’m trying to get some seeds that do well in our high desert and give me some big, really big tomatoes. Last year I got 3 tomato seeds from a giant grower who grew a tomato over 7 lbs in Ohio. This year I got a pretty large tomato from one of those seeds. I kept the tomato which measured 19 inches in diameter and almost weighed 3 lbs and recently got the seeds. I will try some of these seeds next year as well as other big tomato seeds that I got from another grower this week.  Here’s how you can collect your favorite heirloom tomato seeds.

To collect tomato seeds, cut the tomato open, squeeze and scrape out all the seeds and put them in a little jar with some water. Then put the lid on. Try to not get too much pulp in with them. The seed/water mixture will start to ferment in a couple of days and it might bubble a little which is good. The fermentation will remove the slime on the seeds and the seeds will fall to the bottom of the mixture. When almost all the seeds are on the bottom, pour out the liquid, seeds and pulp through a fine sieve, removing the pulp. Keep rinsing until only the seeds are left. Spread them out on a paper towel to drain the excess water and then put them on another paper towel to finish drying. Before the seeds dry completely I move them around so the paper doesn’t stick to them. After they are thoroughly dry, put them in a ziplock baggie, label and store. You can keep any heirloom tomato seeds this way.

My only concern with collecting tomato seeds is if you plant cherry tomatoes too close to the heirloom tomato you want to keep, they may cross-pollinate so think about where they will be in your garden next spring and don’t plant them right next to each other. Tomatoes aren’t pollinated by bees but by the breeze or are self pollinating. Tomatoes originally came from South America and honeybees came from Europe or Africa so tomatoes aren’t native plants to the honeybee hence they aren’t interested which actually makes pollination easier to control.