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OSU Blue Tomato

Over the winter Colleen from In the Garden Online offered me OSU Blue tomato seeds. Having never heard of this tomato variety and seeing how cool the fruits looked I figured I’d give them a try. Yes, there is a blue tomato and it is as unusual a tomato as you imagine and will see below. My first experience with these tomatoes was trying to get the seeds to germinate, a task that seemed so daunting I was about to throw them away before I noticed the seeds had sprouted. This blue tomato was developed by Jim Myers, OSU's Baggett Frazier professor of vegetable breeding and graduate students Carl M. Jones and Peter Mes. The first thing you should understand about the OSU Blue tomato is that it wasn't developed using genetic engineering, but using traditional plant breeding techniques.

OSU Blue tomato, black tomatoes
Garden helper holding OSU Blue Tomatoes.

When ripened, the fruits of OSU Blue range from purple, blue to a dark, almost black color. Probably the closest to black and purple you’ll ever see in a tomato. ‘Black Prince‘ and ‘Purple Cherokee’ tomatoes have got nothing on OSU Blue tomatoes in terms of color. Professor Myers and his students crossed a domestic tomato plant with the genetic stock of a tomato that included a gene incorporated from a wild relative with anthocyanin-containing fruit to produce a healthier tomato. Anthocyanins are the same class of compounds that produce the healthy pigments in red wine that work as antioxidants. According to Myers, domestic tomato varieties grown and consumed in the United States do not normally produce fruit containing any anthocyanin. Anthocyanins are the same class of compounds that produce the healthy pigments in red wine that work as antioxidants. While other fruits have higher concentrations of anthocyanin (think blue berries); the thinking behind adding them to tomatoes is that more people will be exposed to them. Tomatoes are second only to potatoes in consumption of fruits and vegetables. Americans eat about 90 pounds per person per year of fresh and processed tomatoes according to Peter Boches and Jim Myers, Department of Horticulture, Oregon State University.

OSU Blue tomato showing green side
Green side of OSU Blue tomato not exposed to sun

Anthocyanin is only produced in the fruit in areas that are exposed to sunlight. If the fruit is shaded by a leaf, stem or calyx that part of the fruit will remain green. I noticed that the blue pigment only developed in the top half of tomatoes growing lower on the vine. Intense sunlight lead to the most beautiful purple color; since only the part of the OSU Blue exposed to sun turned purple I would bend the stems in half so sun would reach the bottom half of the tomato. Late in summer there was a dip in temperature that also intensified the color.

Over-ripened OSU blue tomato
OSU Blue tomato: purple on the left and red/purple on the right.

The parts of the fruit that weren't exposed to direct sunlight remained green until the fruit passed the ideal ripe stage and then the green skin turned a red-orange color as illustrated by the picture of the OSU Blue tomato above. According to  Boches and Myers, the genes involved in producing the OSU Blue tomato, Aubergine (Abg), Anthocyanin fruit tomato (Aft) and atroviolaceae (atv), are genes introgressed from the wild species Solanum lycopersicoides, S. chilense, S.cheesemanii, respectively. Honestly, I don't know what any of that means, but I can tell you that when OSU Blue tomatoes are at the purple stage pictured above they look similar to the purple tomatillos I grow in my garden.

Blue tomato and purple tomatillos
OSU Blue tomato compare to purple tomatillo

Unlike the OSU Blue tomatoes grown by Gayla Trail last year my OSU Blue tomatoes didn't produce purple stems and foliage. It seems like a lot of tomato growers are growing this tomato, sometimes known as similar in appearance to Blue P20, and doing some experimenting with crossing it with other tomatoes.

Here's a video of the OSU Blue tomatoes at the end of the season in my garden.

Overall OSU Blue may be the most unusual tomato I have ever seen The color is absolutely beautiful and unlike any tomato I've ever grown before in my garden. The flesh of the tomato isn't as dark as the skin and the over-ripened tomato you see pictured above had red flesh when I cut into it. Other OSU Blue tomatoes ranged from green to purple depending on their ripeness. While these tomatoes may be healthier their taste leaves a lot to be desired. It wasn't bad, but it wasn't great either. I'd grow these tomatoes again just for their looks the blue tomatoes ripening to an almost black color are certainly conversation pieces in the garden. Unfortunately, my batch of OSU Blue tomatoes weren't very seedy and I didn't manage to save seeds from them which is disappointing. If you're new to tomato seed saving see my post on How To Save Tomato Seeds.

Sources: OSU researchers add potential helth benefits to tomatoes/OSU Blue tomato FAQ (PDF).


  1. Wow, those are really cool tomatoes! The coloring reminds me of an eggplant.

  2. Great share on introducing OSU Blue tomato to the world of gardening

  3. Those are beautiful, too bad the flavor isn't quite there. What about the purple tomatillo? How is the flavor? I'd like to try tomatillos for the first time next year but don't really know anything about them.

  4. Anonymous9:15 AM

    I've been interested in this tomato ever since Gayla talked about them.

    So cool.

  5. Oh, wow. They turned out looking even more amazing than I thought they would. I kinda suspected the flavor wouldn't measure up (because that would just be too perfect, to have a tomato that looked that sexy AND tasted great.) :-)

    Glad they grew for you at least. I am still cursing myself for not giving mine more time!

  6. @Emmy, You're right. They are very eppplant colored.

    @Manure Tear, Oh, I'm not introducing it. It's been around a couple of years and other have written and blogged about them in the world of gardening.

    @Wicker Rooftop, If you like green salsa the purples are pretty good too. I grow them mainly because they're an heirloom and I'm trying to expose them to my neighborhood. Tomatillos grow like weeds.

    @Tom, If only it was as tasty as it looked. :0)

    @Smedette, All winter long I looked at those damned pics on Gayla's site just waiting for my foliage to change color and look like the one on her plant and it never happened. Still cool tomatoes.

  7. @Colleen, If not for my slovenly ways I would've missed out on growing them too. When I set them aside to throw them out I forgot all about them and then they sprouted. Wish they'd been better seed producers so I could have at least given you your seeds back.

  8. I was wondering why I got so few in the packet (and was worried you'd think I was just being stingy when I only sent you like 2 seeds or whatever I sent lol). I'll order more this spring and see what happens. I'm just glad that at least one of us got pics of them.

  9. You said they don't taste very good, do you think they could be improved with cooking? Like Blue tomato sauce?

  10. Odd about the taste because the little premie version I tried in August wasn't bad at all. Also, I like the "Mini Me" Brown Thumb. :) (P.S. If that's not your nephew and I've just offended someone, ex-pardon-scuse me.) P.P.S. You're saving me seed, right? P.P.P.S. My purple tomatillos aren't purple yet.

  11. @Colleen, Do you remember if the seeds were really tiny? I didn't save any seeds because they looked abnormally small for tomatoes and figured they were just immature seeds, but then I seem to recall that the seeds you gave me were small as well. Anyway, I hope those tiny seeds weren't viable because I at them all. :0)

    @Alina, They don't taste "bad." They just don't taste like much at all. The most tomato-y flavor came from the ones that I left to turn red orange as pictured above. The purple/blue fruits just tasted like tomato with a bit of something extra. Although, maybe this is because color affects how we percieve flavor? I dunno, I think people tasting these would have to do a blind taste test to get an honest appraisal.

    @Monica, Don't get me wrong, it's not a bad taste. It's just not spectacular for A)The amount of trouble they went through to produce this B)The richness of the color. That's my niece and, sorry, there'll be no seeds from these. In the last paragraph I mentioned that mine didn't produce seeds worth saving.

  12. I have one left from my packet (why the heck didn't I plant that???) It is on the small side, but not abnormally small. Ground cherry seeds are much tinier than the OSU Blue seeds.

    I also found the fish pepper seeds you sent me and I have 2 left. I hope I don't forget to plant them next year.

  13. These are so beautiful! When I was a girl, my mom always let me choose a few things for the garden each year, I always chose all blue vegetables.

    I'm hoping one day I'll see lovely veg like this in floral arrangement at a wedding, how unique would that be?

  14. In a way, I am glad to hear that they are not particularly tasty. I have enough trouble getting Mitchell to eat heirlooms - if it ain't bright red (a la Big Boy), he looks at it with great disdain. No way I'll ever get him to experiment with a blue tomato. I, on the other hand, would love to serve a plate of red, yellow and purple tomatoes - that would be way cool.

  15. How cool is this!!!!! Thanks for telling about this amazing tomato!!! Hope all is well in your world.

  16. I TOTALLY need to grow these next year!

  17. Wow, the color is definitely stunning! Too bad it's not that tasty!

  18. If they grow bigger, they will look like round brinjals ;-) Good findings. And yes I am sure blue tomatoes are good coversation pieces.

  19. Wow,

    That is some tomato. I do not have much room in the veggie garden but this would certainly be a conversation piece in a container!


  20. Thanks everyone for the comments. If you've fallen for this tomato I hope you find one next year. It certainly is pretty.

  21. Anonymous6:52 AM

    If this tomato was crossed from a variety that had parentage which was genetically modified then isn't this a GMO?

    Albeit, the GMO came from another tomato.

    Any opinions?

  22. Anonymous1:24 PM

    Where did you get any information that any of the OSU tomato's parentage was genetically engineered? Are you just guessing or do you have specific info that you could share? Please let the rest of us know, as I won't (knowingly) grow anything in our garden that is either genetically engineered and/or patented. Thanks for any info you may be able to supply.

  23. We got a sprout from a friend in Salem, and they are the most yummy tomatoes!! They seem to take an awful long time to get to the point where they can be picked - about 2 months once they start growing out of the flower. I made sure to snip off any branches that were unproductive to make room for more food to the rest of the bush. They are prolific, taste very good, have a perfect firmness to them (not mushy), and grow to about 1-1/2 inch in diameter. Am hoping to save seeds for next year!



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