How to Save Tomato Seeds (and Oddball Varieties)
I have a request! I’d be so delighted if you’d help me locate any seed strain of the OSU P20 blue tomato. (Scroll to the bottom for photos & more details).
Next, the deadline to submit a post about a food or ornamental plant that you’d recommend for How to Find Great Plants is this Friday, January 28th. I’ve noticed that I get the most submissions right before the deadline so I hope a lot of you are still planning to participate in the upcoming issue.
For those of you who haven’t heard, Diana at Kebun Malay-Kadazan Girls is hosting “seed week” from the 22nd – the 29th. I think seed week is more up my alley than shark week, so I’m happy to contribute!
This year I saved seed from dill, achocha, sunberries (Solanum burbankii), garden huckleberries (Solanum melanocerasum), ground cherries (Physalis pruinosa), Zinnia ‘Red Spider,’ papalo, sword beans (Canavalia gladiata), and ‘Reisetomate aus Siebenbürgen’ tomato.
For the most part these were easier for me to save because I was only growing one variety of that species. I rarely save seeds from vegetables that I grow multiple varieties of because it is more challenging to isolate them and prevent unwanted cross-pollination. For example, I know that my ‘Lemon’ cucumber is unlikely to give me seeds that will grow identical fruit the following season since its unprotected flowers occupied the same garden space as the varieties ‘Pearl,’ ‘Arkansas Little Leaf,’ ‘Poona Keera,’ and ‘Kyoto 3-Feet.’ If I planted seeds saved from these cucumbers it would give me fruits with completely unpredictable fruit appearance and taste.
Tomatoes, however, are an exception to that rule… most of the time anyway. The seed-savers FAQ archives on Gardenweb says,
“Tomatoes are generally self-pollinated so there is rarely a chance of cross-breeding. If you save and trade your seeds you might wish to describe your trade offering as “open-pollinated” tomato seeds. That way the trader knows that Mother Nature was solely involved in the fertilization of the flower which produced the tomato that you have saved seeds from.”
Likewise, Jack Rowe’s Seed Saving Handbook says,
“Self-pollinating plants which fertilize themselves before their flowers open (such as tomatoes and beans) are exclusively self-pollinating. These do not need to be isolated under normal circumstances, since by the time their flowers open they will have already pollinated themselves. These plants also benefit from being shaken if they are grown where wind and/or bumblebees cannot shake their flowers naturally.”
Wikipedia explains the science of it,
“Sonication or buzz pollination is a technique used by some bees to release pollen which is more or less firmly held by the anthers, which makes pollination more efficient. The anther of buzz pollinated species of plants is typically tubular, with only an opening at one end, and the pollen is inside – smooth-grained and firmly attached. With self fertile plants such as tomato, wind may be sufficient to shake loose the pollen through pores in the anther and accomplish pollination. Visits by bees may also shake loose some pollen. However, the most efficient pollination is accomplished by a few species who specialize in sonication or buzz pollination.”
I have grown out dozens of packets of home-saved “open-pollinated” tomato seeds and they’ve always come true to type. However, one time I purchased a transplant of ‘Opalka’ from a seed saver that was probably contaminated by cross pollination. It had massive, oxheart shaped fruits with streaked skin like a ‘Speckled Roman.’ I ended up not minding since it tasted fantastic… it probably could have won some giant vegetable awards at the county fair, too.
Speaking of weird tomatoes, I think ‘Reisetomate aus Siebenbürgen’ must be the epitome of oddball heirlooms with a rich flavor worthy of the space in your garden. I wrote about our experiences with it here if you’d like more information.
Since my original source only sent me 5 seeds it was high on my priorities as home-saved variety.This isn’t difficult, but it’s also not as simple as stuffing some dried seed heads in an envelope.
Saved tomato seeds require a small amount of processing once you’ve harvested them — a fermentation method that is supposed to improve viability and kill seed-borne diseases. Here’s how you do it:
First, save the best tomatoes from all of your healthy, highest quality plants (of that one variety). The more plants you have, the more genetic diversity ends up in your saved seeds. Fortunately, the seeds are ripe when the tomato is ready to eat so you can plan to make salsa or some other recipe from the remaining flesh when you finish.
Tomato seeds don’t require cold stratification (a period of cold before germinating) so to keep next year’s seeds from germinating too soon, the gel coating the seeds developed growth inhibitors. When that gel coating rots away the seed becomes free to germinate. Fermenting the seeds at home mimics Mother Nature and prepares them for the following season.
You’ll need to collect the gel and seeds from your tomatoes. Regular, round tomatoes are a little easier to save seeds from since you can simply slice them in half instead of pulling apart the protuberances and then slicing them in half. I tried slicing the whole Reisetomates in half but their chambers were often unconnected and I couldn’t squeeze out the gel. If it won’t squeeze out like a lemon half, you can also scoop it out with a spoon. Meaty beefsteak types are a little more challenging, too.
But your goal is just to squeeze the gel and seeds into one container per variety. If you’re saving multiple containers of seeds be sure to label them with the variety name. Otherwise you’ll be playing eeny meeny miny moe when it comes time to package them.
The mixture of gel, juice, and seeds should have a thin, soupy consistency — the seeds should be floating in liquid. You can add some water to your container if it is mostly solids.
Fruit flies can be a problem so you’ll need to cover the container and make sure it has some ventilation. A cloth or paper towel with a rubber band around it will work well. Then, put it in a warm place such as on top of the refrigerator, on a water heater, or next to a sunny window (I put mine on top of a heated aquarium).
Once a day you should stir the mix to help separate the seeds. Good, viable seeds will sink to the bottom whereas most the pulp rises to the top. After about 2 – 4 days a fungal film should completely cover the surface of the liquid. If you used a clear container, you may also see air bubbles rising up through the fluid to the surface.
When this happens it is time to prepare your seeds for drying. Don’t procrastinate! I’ve had friends who left their seeds to ferment too long and they actually germinated in the stinky liquid. Also, this project is not potpourri — the sooner you eliminate it from your home, the happier your nose will be. (But if you put it in an out-of-the-way place you won’t notice the smell except at stirring time).
Some people leave the fungus through the rinse cycle but I gently scoop the film off and discard it in my compost bin. It’s okay to throw out the “floater” seeds that are caught in the white mold — supposedly they won’t germinate, anyway. I do, but it has more to do with the fact that slime handling gives me the heebie jeebies. Once the mold is gone I pour the seeds into a sieve and rinse them until the pulp disappears.
Once the seeds are rinsed I spread them out on parchment or waxed paper that I place in my bathtub. I leave them there to drain for about an hour before moving the parchment to a regular table.
Trying to spread wet, furry seeds into a single layer is about as challenging as stretching out pizza dough for the first time. If they persist in sticking together just come back a couple hours later and try again. They need to air out for at least a week in open air, stirring occasionally. The seeds are finished when none of them stick together (you’ll have to gently crumble some of them apart), they slide freely across the paper, and they feel completely dry. This should take no more than 2 weeks unless you have an unusually humid environment.
Now you can put them in a seed packet, label it, and store it for the following season.
I’ve composted parchment paper after use but I just read that it is impregnated with silicone… not a natural wax as I had assumed. This year I think I will try drying my seeds on a flat cloth napkin. Does anyone have experience with this? It seems like you could easily peel seeds off of a fabric napkin if they happened to stick.
If your seeds have any residual dampness and you store them in airtight plastic envelopes they will mildew and ruin. However, it isn’t safe to use heat to speed the drying process (it can kill the embryos). Tomato seeds (stored properly) are viable for 8 – 12 years or more.
I like to store mine in paper packets because it gives you some leeway on the moisture and mold problem. Plus paper is fun to decorate! I’ve been making a lot of stamps lately so I decided to carve one to use for labeling my ‘Reisetomate Aus Siebenbürgen’ packets.
I get my supplies from Stampeaz.com but you can also get (pricier) stamp carving medium from craft supply stores. Once I’ve transferred my image to the stamp medium (the lettering has to be carved in mirror reverse) I use an X-Acto knife and a small gouge to remove the negative space.
For this project I made 3 stamps and tried a few different options for applying them to the coin envelopes I use as seed packets. You can also use recycled paper to fold your own envelopes:
- Making a Paper Envelope @ ICPS Seed Bank
- Origami Seed Packets @ The Cheap Vegetable Gardener
- Origami for Seed Savers @ Hayefield
- Origami Seed Packet @ Downsizer.net
- Origami Envelope @ Gillian Crackers
- Seed Envelopes @ Blossom Swap
- Flower Seed Packets @ Squidoo
- Seed Envelopes @ eHow
- Seed Envelope Patterns @ Caustic Musings
Which brings me to the seed I currently want…
These tomatoes are from research and (non-GMO) breeding done by Oregon State University. I understand there are some different strains now but they come from a variety referred to as P20. Some people seem to love the flavor and others don’t… I’m not sure if that’s because the tomatoes are variable or because human palates are variable. Maybe a little of both.
*Edit* Thanks to Robin from The Gardener of Eden for helping me find some!
So, happy “Seed Week” everyone and don’t forget to submit your blog post for How to Find Great Plants! The deadline is this Friday (it will be published on the following Monday). Remember you can reuse a post you’ve already written, here’s the link: