tedln
Super Green Thumb
Posts: 2179
Joined: Thu Jun 25, 2009 6:06 pm
Location: North Texas

How to Save Tomato Seeds

I typically won't attempt to save seed of tomato varieties which can easily be purchased at one of the small, family owned seed vendors. This year, I will be growing a few varieties which I have traded for and are fairly rare. Next year, I plan on growing a large number of rare but interesting varieties. I'm wanting to get my "seed saving" skills perfected and I have a few questions which haven't been answered in any of the videos I've watched.

1. Should the tomato or tomatoes you intend harvesting seed from be left on the vine until fully ripe, or is it even better to leave the tomato on the vine until it is overripe? I want to insure the seed is fully mature before harvesting it.

2. Most seed saving instructions say "when the mold forms on top of the fermenting liquid, the fermenting process is complete. The seed should not be left in the fermenting liquid "to long" or they may start to germinate or turn black and be damaged". What is "to long"? Is a few hours or a few days "to long"?

3. What is the best surface to dry the fermented seed on? I think paper towels or coffee filters may stick to the dried seed. Would small paper plates work? If I sprayed a paper surface with a non stick product like pam to prevent seed from sticking, would it harm the seed?

4. I've found the bleach treatment process to work well to assist in germination of reluctant seed. I typically use it when an original planting of seed doesn't germinate at all or only a few of the seeds germinate. I typically plant the treated seed immediately after treatment. Would it harm the newly saved seed to bleach treat it in bulk before drying it?

5. Would a product like talcum powder or Diatomaceous earth assist in maintaining low moisture on the seed surface while in storage?

Ted

TZ -OH6
Super Green Thumb
Posts: 2097
Joined: Fri Jul 25, 2008 7:27 pm
Location: Mid Ohio

I put a seed prep post in the seed trade forum last summer with links to pictures.

Tutorial: How to Save Tomato Seeds

1) Seeds are mature before the green tomato starts to turn color, but fermentation proceeds better with a ripe tomato (more juice to feed the microbes).


2) Mold does not need to form. Various yeasts and bacteria in solution do the actual work, not fuzzy molds growing on top. The gel has usually broken down by days 3-5 at room temperature. You can see by how the seeds clump together in solution. You can go 7 days or more if you forget. Some seeds may start to germinate while fermenting but those are usually from fruits that were unusually slow slow to ripen, not from fermenting too long.

3) I like to use use non waxed paper plates and blot the seeds with folded paper towel before fluffing them (so they don't stick to the plate). Once the seeds are dry (5-7 days is a good minimum wait) the plates can be stacked until you get around to packaging. Make sure to pencil the variety name on the plate. Watch out for mice!

4) Bleach (more than a quick dip) is best after drying/before planting as it can cause damage and reduce storage life. See the post on potato seeds for discussion of chemical treatment.


Here is info on chemical treatments
-- about 1/4 way down page

https://www.helpfulgardener.com/forum/viewtopic.php?t=27200



5) I would say no. There are drying chemicals (Drierite dessicant, and silica gel) Nobody really bothers. Carolyn Male uses paper envelopes, Craig Lehoullier uses pill vials. Both keep their extensive seed collections at room temperature. Freezers are naturaly low humidity so if you plan on long term storage (7-10 years or more) I would go that route.


It not rocket science although most "how too" instructions make it seem that way.

User avatar
Gary350
Super Green Thumb
Posts: 7396
Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

This is works good for me. Save an over ripe rotten tomato because I know the seeds are mature. Put the bad tomatoes in a bucket of water and squeeze out all the seeds. Water will wash away the enzymes that keeps the seeds from growing. Strain the seeds from the water then lay them on a paper towel to dry. Store seeds in a paper bag just incase they are not dry they will won't mold and will be dry soon. Mark the bag with the name of the tomato seeds. Keep the seeds in a good place until spring.

When I have a large number of seeds I never buy plants. I sprinkle lots of seeds in a row and let them grow. Thin out the plants I don't want.

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

The most important things to remember if you are planning on saving your own seeds from anything are:

1. Save seeds only from open pollinated and not hybrid plants. Hybrids will not come true from seed

2. Do not save seeds from every tomato. Select seeds only from the best and healthiest plants. This is what people do not often get. You don't eat the best fruit off the best plant. You save at least one or two of the best fruit for seeds. Anything that wasn't tasty or were stunted, diseased, small or had defects-- make tomato sauce.

3. It is better not to plant a large variety of different tomatoes close together if you are planning to save seeds. There is a good chance that they may cross pollinate. Tomatoes are wind and insect pollinated. You may have to isolate your tomatoes. plant them in blocks or plant fewer varieties if you want to save seeds.
https://www.southernexposure.com/isolati ... zp-35.html

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

If you are not saving seeds long term or are going to plant in succession, I don't ferment at all, I just sqeeze the seeds out directly on the media. They germinate well enough when the seeds are fresh.

Bobberman
Super Green Thumb
Posts: 2437
Joined: Mon Nov 15, 2010 10:31 pm
Location: Latrobe Pa.

I put the cut up tomato in the blender at low speed with two cups of water. the seeds will settle to the bottom of the blender the rest of the tomato parts will float to the top. Pour out the water slow and the seeds will remain at the bottom. tThe last small amount of water and seeds I pour on a paper towel and run a fan on it a few hours and my seeds are ready to place in a plastic zip bad including the paper towel. When the time comes to plant I simply scrap the dry seeds from the paper towel and they seem to grow at a high percentage. I have been doing it for 20 years!

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

If you use a food processor to centrifuge the seeds, it is better to use the dough blade since it isn't sharp so will damage fewer seeds.

tomc
Super Green Thumb
Posts: 2661
Joined: Sun Apr 10, 2011 2:52 am
Location: SE-OH USA Zone 6-A

tedln wrote:1. Should the tomato or tomatoes you intend harvesting seed from be left on the vine until fully ripe, or is it even better to leave the tomato on the vine until it is overripe? I want to insure the seed is fully mature before harvesting it.
Over ripe fruit can contain already germinated seed. Based on my direct trial if its ripe enough (or has ripened off-vine enough) to eat, its good for seed collection.
tedin wrote:2. Most seed saving instructions say "when the mold forms on top of the fermenting liquid, the fermenting process is complete. The seed should not be left in the fermenting liquid "to long" or they may start to germinate or turn black and be damaged". What is "to long"? Is a few hours or a few days "to long"?
Fermenting tomato in August, scum should form in a few days. Check on third and subsequent days. Once you see it, its time to finish seed.
tedin wrote:3. What is the best surface to dry the fermented seed on? I think paper towels or coffee filters may stick to the dried seed. Would small paper plates work? If I sprayed a paper surface with a non stick product like pam to prevent seed from sticking, would it harm the seed?
IMO seed peels off coffee filters just fine, Less well off of paper plates. I never use pam, I suspect it would interfere with drying. Dry tomato seed is what I want.
tedin wrote:4. I've found the bleach treatment process to work well to assist in germination of reluctant seed. I typically use it when an original planting of seed doesn't germinate at all or only a few of the seeds germinate. I typically plant the treated seed immediately after treatment. Would it harm the newly saved seed to bleach treat it in bulk before drying it?
No
tedin wrote:5. Would a product like talcum powder or Diatomaceous earth assist in maintaining low moisture on the seed surface while in storage?
For air dried seed (like tomato) I never add adulterants, They tend to collect moisture and cause seed to decay.

tomc
Super Green Thumb
Posts: 2661
Joined: Sun Apr 10, 2011 2:52 am
Location: SE-OH USA Zone 6-A

If you were saving tree seeds you might want to support their moisture with some peat moss.

Tomato seeds you want a very low residual moisture. Store them in breathable container (like paper) or only after you are certain they are dry as a mummy's butt (in plastic-bottles).

I have only had scum fail to form with very tiny samples. if I collect them by the quart, this is never an issue.

Bobberman
Super Green Thumb
Posts: 2437
Joined: Mon Nov 15, 2010 10:31 pm
Location: Latrobe Pa.

Blender blades do not harm the seeds at low speed! I use rip tomatoes or from tomatoes that I to take a few seeds from! The paper towel keeps them dry even when in a plastic bag. I collect tomato seeds the easy way and clean seeds the fast way! Fermenting seeds to me is a waste of time because just like using too ripe of tomatoes the seeds in fermenting can start to sprout which will hurt their storage ! I can get a 100 seeds from the blender in a minute clean and ready to dry! I put the ground up tomato pieces in the compost!

DigForVictory
Full Member
Posts: 11
Joined: Sun Feb 15, 2015 6:53 pm

Would these steps be the same for saving tomatillo or ground cherry seeds?
I have some tomatillo from the grocery store and might give seed saving and growing them a try even though there probably poor quality hybrid ones. I figure I might as well experiment now so I mow what I'm doing when I have heirloom tomatoes this fall (hopefully)

User avatar
TomatoGirl
Senior Member
Posts: 114
Joined: Wed Jun 15, 2016 4:34 pm
Location: Ontario, Canada

I use very ripe tomatoes. I then scrape out the seeds and spread on to a paper towel and let this completely dry for at least a week. Next year I just pick the seeds off the paper towel and plant them. Super easy, never failed method.

Algida
Full Member
Posts: 45
Joined: Sun Apr 03, 2016 5:38 am

I also use ripe tomatoes.
I wash the seeds in a tea colander like Image

under tap water jet. Then let them to dry on a small plate, with a label under it, for later identifying the plant.
Storing in several paper envelopes (depending on the number of varieties) .
Usually, not storing seeds more than one year.

Farmerboy
Full Member
Posts: 17
Joined: Mon Mar 20, 2017 9:54 am
Location: Southern Oregon

I have used this method of saving Tomato Seeds for 46 years with almost 100% success.
Choose a ripe Tomato with all the qualities you want, such as nice shape, color, no blemishes, etc.
Spread a Paper Towel or Napkin on the table. Write the name of the Tomato on the paper towel or napkin and the date.
Slice the tomato. Use a knife tip to pick out the seeds and smear them onto a Paper towel or Napkin. Separate the seeds if they are in a clump. You want individual seeds.
Let them dry on the paper towel. Fold the paper towel or napkin and store in an envelope. Write the name of the tomato and date on the envelope .

When you go to use the seeds, tear off a tiny piece of the paper towel or napkin with a seed on it and plant the paper with the seed stuck to it. The tomato seed will germinate and grow. Just like planting one of those paper strips with seeds attached. I repeat I have almost 100% success for the past 46 years using this technique. No fermenting or other processing necessary.

User avatar
TomatoGirl
Senior Member
Posts: 114
Joined: Wed Jun 15, 2016 4:34 pm
Location: Ontario, Canada

I do the same except I pick the seeds off the paper.
I've had 100% germination the past 2 years I've been doing it like this.
I like to get my seeds from the biggest tomatoes too.
Farmerboy wrote:I have used this method of saving Tomato Seeds for 46 years with almost 100% success.
Choose a ripe Tomato with all the qualities you want, such as nice shape, color, no blemishes, etc.
Spread a Paper Towel or Napkin on the table. Write the name of the Tomato on the paper towel or napkin and the date.
Slice the tomato. Use a knife tip to pick out the seeds and smear them onto a Paper towel or Napkin. Separate the seeds if they are in a clump. You want individual seeds.
Let them dry on the paper towel. Fold the paper towel or napkin and store in an envelope. Write the name of the tomato and date on the envelope .

When you go to use the seeds, tear off a tiny piece of the paper towel or napkin with a seed on it and plant the paper with the seed stuck to it. The tomato seed will germinate and grow. Just like planting one of those paper strips with seeds attached. I repeat I have almost 100% success for the past 46 years using this technique. No fermenting or other processing necessary.

User avatar
digitS'
Super Green Thumb
Posts: 3925
Joined: Sun Sep 26, 2010 1:10 pm
Location: ID/WA! border

I also use the paper method. However, I live where summer and fall months are very arid with under 20% humidity on most afternoons. I cannot help but think that helps with this method.

Tomato seeds come right off the cutting board onto a paper towel or coffee filter. They will sit out on my deck under a roof for up to 3 weeks. Sunshine hits that location for a couple of hours every afternoon. The seeds and paper are stored in sandwich bags.

I haven't been doing this for 40+ years but about half that length of time ;). Germination success is very good for the first year or so. I have found that store-bought seed has as much variable germination and longevity as my saved seed. That seed is from multiple sources and that probably adds to my success or failure with it. Anyway, I try to be sure to have fresh seed by the fifth year if not sooner. That rule of thumb also came from experience.

Steve

User avatar
Dissily Mordentroge
Senior Member
Posts: 137
Joined: Fri Jan 29, 2021 5:36 am

I’ve successfully used my father’s method since the 1950s. Place untreated seeds on a sheet of newspaper and allow to dry. Place another sheet on top and write the name of the variety on the paper’s edge. Store in a cool dry place.
When ready to plant I cut around each seed and plant with the piece of paper.
Never had any problems with this method although I suspect it wouldn’t work in a humid tropical climate.

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Actually, an alternative to fermenting has always been to wash the fresh seeds in a strainer until all the gelatin is washed off and then dry it. Fermenting and washing is not the problem. In a humid climate it is hard to get the seeds less than 30% moisture. So, I store the dried seed in a paper towel inside of a ziploc bag. If I have dessicants, I can store multiple seeds in paper towels in individual paper envelopes inside one large zip loc bag with the dessicant. If it stores right the paper towel will not collect any stain.

Most of the time, I will actually plant the fresh tomato seeds and not store them. I can keep tomatoes continuously throughout the year. Most tomatoes will last about 10 months if they have good disease resistance. This is how I keep the sweet pea currant going.

abhaykale
Full Member
Posts: 23
Joined: Thu Sep 14, 2023 7:49 pm

Would the method work for frost damaged tomatoes as well?

User avatar
applestar
Mod
Posts: 30514
Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

Frost damage won’t affect quality of seeds as long as the fruit has reached at least blushing stage. Better/most fully developed seeds inside if they are fully colored and ripe. If frost is due to extended freezing temperatures. there might be some question of viability if longer than 4 to 6 hours in subfreezing temperatures (but I’m sure you would call that a “freeze” event).

Basic rule of thumb, when cleaning the seeds, rinse out all contents of strainer in a bowl of water. Carefully pour off any floaters — BEWARE gel-coated seeds will float even if it’s good and would have sunk without the gel … don’t lose those — add more water, let settle and tilt the bowl in opposite direction to pour off again. Seeds that remain sank on the bottom are the ones to save. Add water final time and return (pour) seeds into (cleaned) strainer to drain and dry.

Well-cleaned seeds with all gel removed will clump together by their seed husk hairs, not stick together due to the gel.



Return to “TOMATO FORUM”