TL;DR: Seeking Canadian gardeners to collaborate on direct-sown tomatoes. Goal: build a diverse, cold-adapted population. Open to seed sharing and trial participation.
Hello,
I’m wondering if anyone in Canada would be interested in collaborating on direct-sown tomatoes.
Primary goal: to generate a diverse population of tomatoes that can reliably produce fruit in northern climates when sown directly outdoors.
Secondary goal: for this population to be used for any other objectives individual gardeners may have: earliness, adaptation, taste…
How it works:
The idea is to save or obtain seeds from interesting projects and grow them outdoors, direct sown. Given the low germination and survival rates, an individual gardener could aim to start with roughly 500–10,000 seeds for 10–200 plants.
Seeds are sown directly 1–3 weeks before the average last frost, and depending on germination, we thin to the most promising plants. We then harvest seeds from fruits that mature before the end of the season.
My experience so far:
Year 1 (2024)
Direct-sowed ~100 seeds from Q Series and Wildlings (EFN) on May 19
Harvested seeds from 1 very promising Q-Series plant and 4–5 others
First mature tomato: August 31
Year 2 (2025)
Direct-sowed thousands of seeds on May 4 (2 weeks before average last frost):
Seeds from Year 1 (~1,000–2,000)
Mission Mountain Grex (100 seeds)
Exserted Orange (2 grams)
Mission Mountain Sunrise (2 grams)
Big Hill (2 grams)
Seeds from Year 1 had the most success, but I’m also harvesting some from the other varieties
First mature tomato: August 17
Looking ahead to 2026:
I plan to harvest as many seeds as possible from this season’s direct-sown plants, as well as from other projects (promiscuous returned tomatoes from GTS have shown promise in terms of earliness).
I’m curious if others would like to collaborate, either through running their own trials or through seed sharing. It could be a great way to explore northern-adapted tomatoes together.
I’m all for it! I will follow through next year with my saved seeds from this years direct sown tomatoes, as well as attempting to do so with the GTS tomatoes seeds I plan to order for 2026.
I sowed my seeds on May 2nd this year but do you specifically want to sow tomato seeds before the last frost?
I have yet to harvest any ripe tomatoes from said plants but I will hopefully contribute some of the direct sown tomato seeds to GTS 2026 dollection and am open to a direct seed swap with you if you are interested.. if i have viable seeds that is
Sounds good! Let’s get in touch later this winter so we can plan some seed exchanges.
I think it’s up to you when you wanna sow, the 2-3 week before last average frost was recommended here, but it’s not an obligation. Also I did plant before my average last frost this year but we didn’t get a frost in that period (it did get down multiple times to 3-4 degrees C even in June)
Oh. I didnt realize there was recommendations listed somewhere on here! Where abouts would i find that? Im still going through the free course through the main site so perhaps i am missing information for certain things.
Of course there are other factors than adaptation such as growing degree days, plantation date, number of seeds planted (increasing each year), inclusion of new genetics, fertility…
But this is going in the right direction!
By the way, this is in an area where people tend to say you need a greenhouse to grow tomatoes…
Inspiring. This makes me want to try and go ahead direct sowing next year already. My strategy was to start and cull heavily in flats sown in cold benches for a couple of years first. This kind of progress seems more efficient.
We’re August 26, 2026 and I’ve been getting multiple tomatoes per plant from direct sown seeds that are from my local line of direct sown tomatoes.
Other lines: Lofthouse direct sown, GTS canada early, 2026 GTS promiscuous canada 2026, seeds saved in my garden from GTS USA promiscuous 2025.
^^ Those lines still have green tomatoes for the most part.
Note that this is very unscientific, could just be I gave more compost to my direct sown line or something like that, or that I planted more seeds…
Also the GTS canada early 2026 seeds include my direct sown seeds, so who knows what’s going on.
Anyway the results are not scientific but Im just happy to be getting red (well mostly orange) tomatoes in Quebec from direct sown tomatoes grown without cover.
Some beds I put dozens of seeds for each tomato spot and thinned to one plant.
One bed I scattered the tomato seeds like a covered crop and raked, then thinned to the biggest plants.
Both techniques worked. I didnt do much else other than put compost, hay, and watering maybe once or twice in total (plenty of rain here however). And a bit of weeding still.
It would be very interesting to cross your results on early maturity with climate data.
If the dates of maturity are moving up in an increasingly favorable climate (warm, humid), perhaps the adaptation project is stalling.
If the dates of maturity are moving up in an increasingly unfavorable climate (warm, humid), perhaps the adaptation project is progressing rapidly.
If the maturity dates are moving up under an irregular climate (a favorable year followed by an unfavorable one), then the project is surely on the right track.
No slug damage, but this year we certainly had a bacteria (fungus?) killing the leaves.
I think this year has been favorable in terms of warmth (more heat but not excessively). We did have some heavy rains (e.g. 13 cm). Probably not enough years in the project to account for climate.
If we were going to do this scientifically, it probably wouldnt be about comparing year to year, but comparing to other genetics under identical conditions. But I’m ok right now just observing anecdotal data.
I guess it’s time I provided an update. The garden I planted in is at my in-laws house so I don’t get up there too often as it’s quite far from my house. It was rototilled by my father-in-law twice before I planted because he hated seeing all the weeds. He’s a farmer so naturally he hates weeds, lol.
The soil is quite compacted and has poor fertility because of decades of regular tilling. I’ve never fertilized it, and they tell me they haven’t added any manure to it in at least 15 years. I’ve had it for the last 5 years.
I sowed on May 31 if I remember correctly, there was heavy rain the next 3 days, and it rained often for the rest of the month. I wasn’t able to get in and weed until early July due to the mud.
I’ve only weeded twice since then, the last time was August 15, which was the last time I was there. I don’t plan on weeding again.
I had no open flowers as of that date, but buds forming on some plants, I pulled out any plants that didn’t have any buds. I think I have around 6 - 8 plants left.
I’ll probably head up there again in the next few weeks, and I’ll try to remember to take a few pictures this time.
I’d like to give this a try next spring. It’s my first year saving seeds, so I’ll have a few hundred extra to devote to this.
Almost nothing grows for me direct-sown… none of my lettuce, carrots, etc ever came up this year. I don’t know if it’s bugs, birds, squirrels, or what. But getting even one direct-sown tomato would be quite an accomplishment.
What kind of spacing are you using when sowing your seeds? If only 1 in 50 seeds is going to make it to seedling, then I’m guessing it’s fine to put 100 or 200 seeds in a 1-foot row?
I don’t have any set spacing for my seeds, I just sprinkle them in fairly thick. If I had to guess I think roughly 15-25 seeds per foot.
I don’t look at them for around a month after planting, so I’m not sure how many germinate, but I’ve never had to do much thinning. They might be germinating and dying after, or not germinating at all.
I have noticed that they tend to come up close together, both years I’ve direct seeded I’ve had some plants quite close together, and 5-10 feet of no plants at all. I have no idea why that is.
If you have a lot of seeds, It may be worthwhile to plant a lot of seeds per foot, but tomatoes can be a large plant in the right conditions so if a lot of them germinate, you might have to do a lot of thinning.
I don’t like to have my tomatoes much closer than 1 foot apart, and if your garden is fairly fertile, I think 2 feet apart would be better.
Mine have been germinating pretty well. But then I find that some seedling grow faster than others so I plan to thin pretty hard. One strategy I followed this year was making ~ 1.5 diameter circles at whatever final spacing I want for a single tomato plant (e.g. 2 feet). On each circle I sowed dozens of seeds (potentially 100++). Then gradually thin to my favorite plant (typically can be done in 2 thinnings).
Another strategy I used last year was to plant 3 rows over the length of the bed. Was suboptimal because you end up not controlling the final spacing that well.
Another one used this year, was sowing seeds like a cover crop and raking. That worked decently, but I did get a few gaps and clusters.
