This easy tutorial shows you how to save seeds from heirloom and open-pollinated tomatoes so you can grow more of the same kind next year.

This is part of a series on 5 Best Tips for Growing Tomatoes.

Easy Seed Saving

Just one tomato yields many seeds and seed saving is really easy. This walks you through the process in eight simple steps.

I grow both heirloom and hybrid tomatoes. For seed saving, you want to save the heirlooms and other open-pollinated seeds. You can also try saving hybrid seeds but they may not grow true to the parent plant or bear fruit although I’m in the camp that loves testing them anyways.

Definitions vary but here is one: heirloom tomatoes are self-pollinators that have bred true for 40 years or more. If you know the name of your tomato plant but don’t know if it’s heirloom or hybrid, just Google the name for an instant answer.

Before you get started, please know there are many ways to save seeds so don’t worry if you see advice that varies. So long as we end up with viable seeds, it’s all good.

Choosing Tomatoes for Seed Saving

The tomatoes must be both mature and ripe, but not over-ripe.

You can tell a tomato is fully mature by cutting it open and examining it. Mature tomatoes have a gelatinous coating covering the seeds inside.

Once a tomato is mature, it can ripen.

Also, fruit quality can vary even on the same plant, so use the best of the bunch for your seed saving.

If your plants suffered some seasonal diseases like blight, this will not affect the quality of the seeds.

Saving Heirloom Tomato Seeds

There are lots of good methods for saving tomato seeds. This old-fashioned method relies on fermentation which occurs naturally during the process.

Step 1

Scoop out the seeds and their gelatinous coating.

Slice the tomato and scoop or squeeze out the seeds with their surrounding goop into a cup. That goop (gelatinous coat) actually protects the seeds from the acid of the tomato.
Add enough water to cover plus one inch. The rest of the tomato is good to eat, of course.
Tag or label the cup with the name of the tomato.

Step 2

Cover and wait 4-5 days.

It will ferment and get moldy and gross.
Nature is genius: the fermenting process releases the seeds from their casings and kills off any baddies/diseases lurking in the tomato. Plus, it looks so delicious, dontyathink? I think Sylvester Stallone drank this in Rocky. Or was that raw eggs?
Some sources say white mold is a good sign. Mine always seems to be green. But, whatever. My seeds grow very well indeed.

Step 3

Rinse away moldy gunk until just seeds remain.

When the fermenting has done its business, pour the gunk into a sieve at the kitchen sink.

Rinse with water until just the seeds remain.

Seeds are amazing. This I know for sure. And they contain eternity. What’s not to love?

Organic Slow-Release Tomato Fertilizer

When ready, you can grow tomatoes in the ground or in containers.

Tomato Fertilizer | Amazon

Step 4

Air dry seeds for seven days and flip daily for even drying.

Place the seeds on a plate to dry out for approximately seven days. My plates have numbers on them. One plate for each type of tomato. Keep track of the names!
I also save wildcard seeds. If I’m chopping tomatoes for a meal and using a bunch of different heirlooms, I just put all the seed glumps into one cup and save them that way. I know I like all of them so I won’t mind whichever kind sprouts next year when I plant them. And it’s like a seed surprise pack.

I cover the plates with old file folders so the fruit flies won’t get too excited while the seeds are drying.

Turn the seeds over each day so they can dry out completely. I reuse my numbered plates and cups over and over again.

When they’re really dry, the seeds will slide across the plate/bowl, instead of sticking to it.

Step 5

Store in labelled envelopes or containers in cool, dry place.

You can read more on best conditions for storing seeds here.
Sources vary saying that saved heirloom seeds will be viable anywhere from 4-10 years. I’ve got some that are 15 years old that still have good germination rates. Good storage is key.
Also, there’s lots of online seed swappers if you want to collect more varieties and share what you have. Power to the people!

That’s all there is to it. Now you’ve got lots of seeds for years to come.