Saving Tomato Seeds

Master Gardener John Coykendall is always happy to talk about his love of heirloom tomato varieties, and he’s quick to tell you his thoughts on how modern tomatoes don’t measure up. “Modern tomatoes will keep forever, and they look great – they all look the same. But they’ve lost all their flavor,” he says.

When John saves seeds, he’s preserving more than pure and delicious tomato flavor, he’s preserving farming knowledge and technique that has been used for centuries.

Tomatoes can be used in any stage. Before they ripen, you can enjoy fried green tomatoes or pickled green tomatoes. A tip from John, he likes to put green tomatoes in the jar with his cucumbers when making dill pickles. He says go half-and-half tomato pieces and cucumber spears, and it’s delicious!

Heirloom tomato varieties naturally have more acidity in their flavor. If you reference a canning book today, the processing time is considerably longer than what a book written in the 1940’s would have called for. If you’re canning with modern tomatoes, you also have to add a couple tablespoons of lemon juice to compensate for the acidity that’s been bred out of the fruit over time.

After the green stage, tomatoes are certainly enjoyed at peak ripeness in all kinds of ways. And then, when you’re ready to save some seeds, you leave the tomato to fully mature. Once the tomato is over ripe, John squeezes the tomato into a glass container so he can watch the process. As it ferments in the jar, the acid breaks down the gelatinous sack around the seeds. The good seeds sink to the bottom of the glass and any “duds,” as John calls them, float to the top. He adds a little water and skims off what’s floating at the top of the glass and then pours the seeds into a strainer. The seeds are rinsed well and left to dry.

When you’re preserving the seed, you’re trying to replicate what nature would do to the plant in the wild. If left alone, the tomato would rot and fall off its vine to the ground. But it’s not going to sprout a new plant until that gelatinous sack dissolves. “It’s kind of like a time capsule,” says John. “It will come up once the process is complete. That’s why you might find cherry tomatoes popping up in the compost. It’s cycled through the Winter and come back to life for Spring!”

When properly dried and preserved, tomato seeds can last a long time, upwards of 10 years. They have a great longevity that not all seeds have. What starts as seeds from a single tomato can turn into years and years of plants.

If you decide to save some tomato seed, John asks for two things. Use a good, old-time variety of tomato that has all the great flavor you’ll love, and don’t forget to pass the plants story down with its seeds.