Tomatoes that self-seed in zone 6 and colder

Hi there,

I'm interested in crops that don't need a lot of attention. The ultimate tomato, to me, is one that I can throw spoiled fruit on the ground in fall and expect it to grow next spring.

This fall I enacted my tomato breeding program by throwing a few hundred tomatoes of 2 varieties, and tomatillos of one variety on the ground. That's just what I had on hand. I planted other varieties back in spring but these are the only ones that produced well.

Next spring we will see if any of them grow. The main obstacle being that in winter here, the tomato fruits and seeds will freeze and thaw repeatedly over the course of almost 5 months. A genetic trait that will really help the seeds survive freezing is probably not easy to find-- but it is easy to select for if you have it.

My question for fellow permies in freezing climates: do you have any tomatoes that have volunteered just from falling on the ground?
Everyone who grows tomatoes has seen a volunteer here and there. (Especially in the compost. This is a confounding factor, however, in that compost generates heat. I'm dreaming of tomatoes that can self-seed on the plain old frozen ground.) If your tomatoes have produced lots of volunteers from fruit that fell on the ground, please let me know more about the variety and growing conditions.

Thanks kindly,
Devon

I hope someone with experience in your area will chime in.

Maybe if you plant a tomato with a short growing time such as Early Girl there might be a chance that by the time the seeds come up (when the weather gets warm enough)and the time the plant produces fruit you might get a few tomatoes before frost season.

This is the main reason many gardeners use transplants.  They can get the plants up and running before the weather gets warm enough.

I have 6-8 months of potential freezes. I've always had lots of volunteer tomatoes of all different varieties. I don't pick all my green tomatoes at the end of the season and leave the plants and fruit as mulch. If I have a tomato I don't particularly like, I'll chop the plant down and leave it in place as well. So lots of rotting tomatoes all over the place.

The problem I have is that my season isn't long enough to get much fruit off the volunteers. They don't start producing until right at the end of the season.

This year I planted some of the shortest season varieties I could find. Jagodka and Brad are used in the breeding work of one of the members here, so I got those. Then I got seven or eight others with names like Manitoba and Sub Arctic Plenty. I planted them in pots outside so they would come up on their own schedule.  I got my first ripe tomato on September 2nd, which may have been a bit later than it otherwise would be because our summer was very challenging for unwatered plants this year. I'm hoping with some seed selection to improve on that date.

So I'd say just plant lots of short season tomatoes and leave lots of fruit from the ones you like.

We got to -18C last year and I got lots of volanteer tomato plants I don't think they mind being frozen as seeds at all. However I get 0 tomatoes from those plants as they germinate to late for my season.

I have one that self-seeds so easily, I've been growing it for 5 years, but only planted it once. It was originally a volunteer from the compost bin, but has popped up everywhere since. I'm tentatively calling it "Mini Paste", because it's the size of a grape tomato, but meaty enough to use like a paste tomato. It's probably just an ordinary variety like Juliet, but unless I run a DNA test there's no way to be sure.

Last year it surprised me. I had a few of them growing where they were easy to harvest every day, but there were also a few in a spot that was hard to get to, and covered in creeping charlie. All I saw of them was an occasional leaf sticking out, so I figured they weren't doing much. Then one day I was out there, and the wind blew in just the right way that it moved the creeping charlie leaves away, and I saw that the ground underneath was carpeted with little tomato fruits!!! The tomatoes had been using the creeping charlie as a shield!

Part of the reason this variety pops up everywhere, is because it's my chickens' favorite treat. They'll grab one out of my hand and chase each other all over the yard with it, so there's no telling where the seeds will end up. At least 6 plants came up between the paving tiles next to the house.

I did not save seeds from this year's batch, but I'll see if I can find some from previous years to share.

Tomato seeds seem quite capable of surviving the winter and volunteering the next year. However, and I don't know why this is, the percentages seem to be lower than for direct seeding. Also it seems like at least in my garden their is a trend towards gradual extinction. For instance in my direct seeding experiments these past five years I have probably left thousands of tomatoes on the vine at the end of the season. My current garden is littered with them. This spring I couldn't find a tomato packet I had saved of one variety I grew a seed crop of the year before. So I walked out to the isolation garden picked up a tomato mummy crumbled it into a pot and grew some more! In that garden however there were no volunteers.

In 2019 I grew a huge direct seeded population of segregating F2's. In 2020 I had a nice little patch of volunteers. I fully expected them to volunteer again in 2021 but they really did not. Evidence towards this trend towards gradual extinction.

Now some of the seeds can survive for multiple years in the ground. It does seem to me like tomatoes really benefit from a one inch or greater germinating rainfall event properly timed.

I've hypothesized that enough years of direct seeding and volunteering could result in tomatoes that volunteer as you wish. However the reality often seems to be this gradual trend towards extinction.

In 2016 I picked up a single plant of Amurski Tigr https://ohioheirloomseeds.com/products/amurskij-tigr-amur-tiger-tomato-seeds
From the tomato plant lady at the Missoula Farmer's market. It seemed to have everything I liked about tomatoes at the time. It was a early season indeterminate and it had stripes!

So in 2017 I did my first big direct seeding experiment and this included seed from the Amurski Tigr plant. It also volunteered. So I put some pollen from it on the exserted stigma of Blue Ambrosia also in my 2017 garden.

In 2018 I direct seeded a huge direct seeding of Blue Ambrosia saved seed.

Then in 2019 the stripes reappeared in my 2019 direct seeding.  

So in 2020 I grew the result out isolated and Snake River Seeds has been kind enough to offer the result in their catalogue.

https://www.snakeriverseeds.com/products/tomato-exserted-tiger#:~:text=%EE%80%80Exserted%20Tiger%20Tomato%EE%80%81%20was%20bred%20by%20Montana%20seedsman,plants%20is%20quite%20the%20accomplishment%20in%20Western%20

In my personal seed collection I also have yellow variants from 2019 and volunteers in 2020.

So in my personal experience Amurski Tigr and it's descendant Exserted Tiger volunteer fairly well. However if they volunteered as well as you hope they would utterly have taken over my garden by now and would have made it impossible to direct seed other varieties in some of my gardens. That has not been the case- though I worried it might be in the garden where I grew the ancestors of Exserted Tigr in 2018, 2019, and 2020, they didn't reappear in 2021 or at least not much and any that did got weeded out because I used the area for a massive grow out of elite material from Joseph Lofthouse's promiscuous project in 2021.

Joseph Lofthouse's promiscuous project is best available from EFN seeds https://store.experimentalfarmnetwork.org/collections/lofthouse?page=1 both the wildling panamorous and the Q series are currently available and look fairly similar to what I grew out. Direct seeding was successful in 2021 but I found no volunteers from the 2020 grow out in my oldest garden. Exserted Orange is also available on the Joseph Lofthouse page and it is one that Joseph sent me in the F2 from Big Hill x Unknown and I reselected for good exsertion of the stigma to match Big Hill which is also available from EFN and Snake River.

This year I also grew a great deal of potentially crossed Big Hill seed direct seeded but didn't select anything from it. Suffice it to say Big Hill, Exserted Orange, Exserted Tiger, Amurski Tigr, and Blue Ambrosia all work direct seeded as do many others.

I would look for tomato varieties of about 60 DTM or less ideally though 70 DTM or greater varieties will sometimes work out direct seeded.

One would think that wild tomatoes would be particularly good at volunteering and direct seeding. In my experience having grown ~12 or so species tomatoes, that is not the case in zone 6a. I believe that is largely because of adaptation- most North American garden habitats do not closely enough approximate the habitats found in South America and the season is shorter here.

One key word there is habitat. I have seen volunteer tomatoes growing in the wild in places like dry riverbeds in southern California near agricultural areas, in areas burned by forest fires where someone may have sat and eaten a lunch while say fighting fire, along sidewalks in Nevada, on city streets in Southern California, in a waste place on the edge of an agricultural field in southern California, and along a trail on the island of Kuai in Hawaii. Disturbance, lack of competition, and riverbeds seem to be key habitat factors. I add sand to my gardens and I do think the gardens that have had sand addition seem to have better volunteerism. That is to say the more your garden is like a dry riverbed the more closely it may approximate natural tomato habitat. There is a book on growing grapes that I read that says that to grow grapes properly the vine yard's soil should be deeply mixed and inverted to mimic something like that of a natural riparian area where grapes grow in the wild. I think something similar may be true of tomatoes. Riparian soils are hard to characterize because they are deeply mixed and layered, there may be patches of sand, cobble, organic material all in layers. So certain soil textures may be favorable or unfavorable to tomato volunteerism!

One intermediate method was reported by a gardener who cowrote a book with Ruth Stout https://www.amazon.com/Ruth-Stout-No-Work-Garden-Book/dp/1927458366/ref=asc_df_1927458366?tag=bingshoppinga-20&linkCode=df0&hvadid=80195748809666&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4583795274845089&psc=1 one Richard Clemence. He grew the variety Ponderosa and every year would bury a few tomatoes in the mulch next to a wooden stake. Then he would dig up those tomatoes in the spring extract their seed, pull back the mulch and replant the seeds  in a row each spring. Their is a very good parallel there with what I did this spring when I walked out and grabbed a tomato mummy and extracted its seed and replanted it. This method might represent a nice way to ensure year to year success without encountering that slow decline towards extinction. One wooden stake and an hour or so of work in spring and fall combined. There need not even be a stake if you get good at recognizing tomato mummies and finding the little ball of seed inside. I could therefore spend an half hour collecting the mummies the spring before I rototill. Crumble the mummies to extract the seed, rototill. Then sprinkle, cover, mark, and weed the row.

There are currently 100's of Lofthouse promiscuous project tomatoes lying rotting on the ground of the direct seeded rows of my massive 2021 grow out. Representing untold thousands of seeds. I don't plan to let them volunteer next year though as I had one plant with so spectacular a flavor I want to dedicate that entire garden to its offspring in 2022 which will because of small seed numbers necessarily have to be transplants.

So if there are volunteers I want to keep I'll likely end up transplanting them! I'm sure I'll put in some direct seeded rows in 2022 though. Maybe the segregating yellow seed I've saved including the packet from the 2020 volunteer yellow sibling line to exserted tiger.

Another key thing I think is weeding. Without some weeding direct seeded and volunteer tomato seedlings tend to disappear. In my experience this can be as little as one weeding event. when everything is about ~6 inches tall or so give or take. Earlier and more frequent weeding seems to give better results but once a bit later is enough. Though it helps to know precisely where the seedlings are likely to appear!

So some questions for you: What are the varieties you spread tomatoes from? What is the texture of your soil that is how much sand, silt, and clay? You can answer the latter question if unknown with the USDA's Web Soil Survey https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm

Jan White wrote:I have 6-8 months of potential freezes. I've always had lots of volunteer tomatoes of all different varieties. I don't pick all my green tomatoes at the end of the season and leave the plants and fruit as mulch. If I have a tomato I don't particularly like, I'll chop the plant down and leave it in place as well. So lots of rotting tomatoes all over the place.

The problem I have is that my season isn't long enough to get much fruit off the volunteers. They don't start producing until right at the end of the season.

This year I planted some of the shortest season varieties I could find. Jagodka and Brad are used in the breeding work of one of the members here, so I got those. Then I got seven or eight others with names like Manitoba and Sub Arctic Plenty. I planted them in pots outside so they would come up on their own schedule.  I got my first ripe tomato on September 2nd, which may have been a bit later than it otherwise would be because our summer was very challenging for unwatered plants this year. I'm hoping with some seed selection to improve on that date.

So I'd say just plant lots of short season tomatoes and leave lots of fruit from the ones you like.

I think this is your best chance of developing a usable variety that reliably self seeds.

One problem I have seen is that I get tomato seedlings popping up all over my 6a garden in the spring but most often they either get killed off with late frosts or germinate too late to supply useful fruit. Finding a variety with short season that can delay germination would be key to developing a viable freely reseeding variety.

john Harper wrote:

Jan White wrote:I have 6-8 months of potential freezes. I've always had lots of volunteer tomatoes of all different varieties. I don't pick all my green tomatoes at the end of the season and leave the plants and fruit as mulch. If I have a tomato I don't particularly like, I'll chop the plant down and leave it in place as well. So lots of rotting tomatoes all over the place.

The problem I have is that my season isn't long enough to get much fruit off the volunteers. They don't start producing until right at the end of the season.

This year I planted some of the shortest season varieties I could find. Jagodka and Brad are used in the breeding work of one of the members here, so I got those. Then I got seven or eight others with names like Manitoba and Sub Arctic Plenty. I planted them in pots outside so they would come up on their own schedule.  I got my first ripe tomato on September 2nd, which may have been a bit later than it otherwise would be because our summer was very challenging for unwatered plants this year. I'm hoping with some seed selection to improve on that date.

So I'd say just plant lots of short season tomatoes and leave lots of fruit from the ones you like.

I think this is your best chance of developing a usable variety that reliably self seeds.

One problem I have seen is that I get tomato seedlings popping up all over my 6a garden in the spring but most often they either get killed off with late frosts or germinate too late to supply useful fruit. Finding a variety with short season that can delay germination would be key to developing a viable freely reseeding variety.

I would say one additional element is needed in variety development: the potential for genetic segregation. You can gain this potential by starting with hybrids, making crosses, or acquiring varieties that are more likely to cross on their own.

Hybrids: In 2017 when I first got serious about direct seeding I acquired all the shortest season tomatoes I could including the hybrids! One that worked particularly well was Sungold which is an F1 hybrid. There are quite a few early season F1 hybrid tomatoes on the market!

The second way is to make crosses. There are lots of videos available on youtube for how to do this! https://www.youtube.com/watch?v=3aj5TPzhDuI

The other easy source for this potential in my experience is searching for varieties with a trait where the female part of the flower tends to poke out a bit. That is what I found with Joseph Lofthouse's Big Hill and another variety called Blue Ambrosia. This trait leads to a greater rate of crossing. I've tried to capture that trait in Exserted Tiger (descended from Blue Ambrosia x Amurski Tigr) and Exserted Orange (Big Hill x Unknown). Exserted means "sticks out a bit". You will be able to find the crosses when you save the seed from one sort and it turns out quite different. For instance red tends to be dominant so if you plant any sort of yellow tomato like Big Hill and it turns up red the next year you have a cross!

Also and on a separate note: I have hardly any tomato disease issues here. You may have many more on on the East coast? I grew some of my tomatoes on a shady balcony in Missoula MT last summer and the powdery mildew!

Oh and for whatever reason here my volunteers and direct seeded tomatoes almost never germinate before the last frost- they did a bit in 2017 but then mostly survived it at one inch in height. So the other four years germination was well timed. If a one inch rainfall event doesn't happen at the proper time here tomato seeds need to be watered to germinate. Rain virtually stops in March and April here and then we tend to get hammered by rain in May and June.

I had about a dozen volunteers from tomatoes that were tossed on the ground or were in the compost pile. Unfortunately, I didn't record what they were because I didn't expect them. Nevertheless, very few produced anything as they germinated too late.  

Paul Sofranko wrote:I had about a dozen volunteers from tomatoes that were tossed on the ground or were in the compost pile. Unfortunately, I didn't record what they were because I didn't expect them. Nevertheless, very few produced anything as they germinated too late.  

That is about where I was in 2016 when I first noticed two volunteers that barely produced. In 2017 I collected tons of short season tomato varieties and tried them all direct seeded. With more deliberate selection direct seeding and volunteers are much more productive in zone 6A. Though they do produce a late crop

Some of the results of that 2017 direct seeding were as follows:

Earliest:
Sweet Cherriette
Jagodka
sungold F3
Anmore Dewdrop

Almost as early:
Tumbler F2
Krainiy Sever
42 Days
Coyote
forest fire

Female part of the flower sticks out and early enough to direct seed:
Blue Ambrosia
PL Matina
JL potato leaf

Fancy and early enough to direct seed:
Blue Ambrosia
Amurski Tigr

tasty and early enough to direct seed:
Sungold descendents
Blue Ambrosia
Possibly yellow pear (in a good year like 2017!)

Other interesting:
Dwarf Hirsutum Cross "jeepers" exceptionally healthy plants and worked direct seeded.

I would add in subsequent years I have discovered or bred some additional very interesting tomato varieties all of which I think will work direct seeded or as volunteers:

Big Hill (Bred by Joseph)
Exserted Tiger (Bred Blue Ambrosia x Amurski Tigr)
Exserted Orange (Bred w. Joseph and others)
Joseph Lofthouse's promiscuous tomato project
Brad (A favorite of Joseph's)
Wild Child- bred by same guy as Blue Ambrosia a very early stabilized wild cross
I have one project I call Mission Mountain Sunrise or MMS for short. It is a very fun blue bicolor but is so far unreleased.
Also I would add there are at least two strains of Jagodka and the strain I obtained in 2017 was different from Joseph's strain. Which is funny because it was really good but I only got it because Joseph said so much about his strain! If I were interested in boring red tomatoes I would cross the two strains and call it Jagodka x Jagodka. I don't know for sure if Josephs strain is as early as Earl's strain. Also Anmore Dewdrop is a stabilized version of Tumbler f1. So if you want hybrids to start with I would highly recommend Sungold F1 and Tumbler F1.

2018 was the only year that was a little iffy. I got a freeze after I got a good amount of tomato seed back but before I got the amazing production I got in 2017. Though the early produced F1's from 2018 led to an amazing F2 year in 2019! Maybe my favorite year so far!

I forgot to mention earlier, I do have some tomatoes that come up volunteer that put on significant crops and that's cherry tomatoes. Most of them are no i.d. crosses, but the black cherry that I planted several years ago has come up every year and reseed itself in the same location and they are very prolific little cherry tomatoes with that characteristic delicious dark tomato flavor.

I have an unintentional cross that I perpetuate of black cherry and probably Brandywine that I call Prieta Linda. They make delicious saladette or plum sized tomatoes that produce well with some tending more towards black cherry and others tending more towards Brandywine.

My strain of Solanum pimpinellifolium has been reliably volunteering in my community for decades.

It does not reliably volunteer in my garden. It has a huge population of tomato flea beetles.

I received a report last year of an F1 pimpinellifolium hybrid volunteering in a neighbor's garden. It was a small cherry tomato instead of a current tomato.

Tomatillos reliably volunteer in my garden, and in gardens throughout my community.

This fall, I gathered tomato vines, with lots of fruit, and threw them into the badlands. Just an experiment to see if any of them can learn to grow,

I'm in zone six and tomato volunteers of all types are extremely common in my garden. I generally treat them as unwanted weeds because I save seeds from my favorite plants and want them instead. Only exception is the pimpinellifolium and their crossed offspring witch I recognize by the distinctive leaves, I always let some of them grow or sometimes transplant them to a more appropriate spot.  I have on occasion found them outside the garden and even outside the mowed part the yard. Pretty tenacious to compete with the tall grasses and other weeds that occupy those areas. I also don't know how they get there, critters I reckon.

William Schlegel wrote:So some questions for you: What are the varieties you spread tomatoes from? What is the texture of your soil that is how much sand, silt, and clay? You can answer the latter question if unknown with the USDA's Web Soil Survey https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm

The varieties I have already rotting in the field are Wapsipinicon Peach, a Roma tomato, and Rio Grande Verde tomatillo, all of which take around 80 days. There was one random currant tomato plant growing in there, which I don't remember planting any of.

The soil is silty clay loam with low organic material. The fields are at the top of a gentle hill, so well-drained. There are at least 130 frost free days here.

It rains a lot. I do not irrigate at all. I've only been growing in this area for 3 years and this plot for 1 year, but my experience so far is tomatoes were disease-free through the summer when heavy rain storms are followed by intense sun. In early october disease started to set in as the sun was no longer strong enough to dry the surface of the ground after rain. But I still had some unmarred tomatoes right up until the freeze.
Considering how much rain we get, I think low organic matter might actually be helpful to preventing tomato disease, as the surface dries quickly, though it almost never dries 2 inches down.

A 1-inch rain event typically happens every month here. A hard frost after reaching tomato-germinating temperature is rare but it happens some years.

Hand-weeding each bed once or twice per season is my preferred weed suppression method and seems to be sufficient. I also use mulch for some things, but unfortunately mulch interferes with self-seeding.


I immensely appreciate the information everyone has posted here so far. Clearly a short season is going to be one of the most important factors, plus germination that is delayed long enough to avoid a late frost. And of course the good old "I dunno why but this one makes lots of volunteers." I'm forming a good list of varieties to start with.

I've found that tomato seeds germinate well in wood chips, undisturbed since the tomato fell on them, and since most weeds don't you get a big advantage. I have a lot of tomatoes that fall to the ground and get left there.
I only grow a limited number of heirloom beefsteak varieties. Mortgage Lifter is my shortest to harvest.  I also grow Dester, Pink Brandywine, Pink Ponderosa, and Belgian Giant. So the volunteers are one of those, but I don't know which.

John Indaburgh wrote:I've found that tomato seeds germinate well in wood chips, undisturbed since the tomato fell on them, and since most weeds don't you get a big advantage. I have a lot of tomatoes that fall to the ground and get left there.
I only grow a limited number of heirloom beefsteak varieties. Mortgage Lifter is my shortest to harvest.  I also grow Dester, Pink Brandywine, Pink Ponderosa, and Belgian Giant. So the volunteers are one of those, but I don't know which.

Then I will experiment with mulch. About half of my current rotting tomatoes are on a thin layer of mulch-- it's from early spring so it's significantly decomposed. In the coming season I may try applying mulch at different times for comaprison.

John Indaburgh wrote:I've found that tomato seeds germinate well in wood chips, undisturbed since the tomato fell on them, and since most weeds don't you get a big advantage. I have a lot of tomatoes that fall to the ground and get left there.
I only grow a limited number of heirloom beefsteak varieties. Mortgage Lifter is my shortest to harvest.  I also grow Dester, Pink Brandywine, Pink Ponderosa, and Belgian Giant. So the volunteers are one of those, but I don't know which.

Intriguing! Wood chips, bark, and sawdust at least temporarily create a more open soil texture similar to sandy or gravelly soils. Similar to those soil textures found in seasonally dry riparian areas where I have seen volunteer tomatoes. Also, in seasonally dry riparian areas you tend to get little drifts of organic materials such as branches, sticks, or leaves. Soil texture could also explain the good germination out of compost piles.

Pink Ponderosa would be that same variety or a close relative that Richard Clemence wrote about with Ruth Stout. It would make sense that it would still work.