Sunday, 20 September 2015

OSU Blue tomato

I have grown a lot of interesting tomatoes over the past few years, one of the more interesting tomatoes I grew last year was the OSU Blue tomato.  I have had a lot of questions over it so thought I would write a blog post.
OSU Blue tomato
OSU Blue was one of the first high anthocyanin tomatoes, it was bred using conventional methods (ie NOT GM).  In case you were wondering "OSU" is an acronym for Oregon State University.

From what I have read this tomato was developed by Jim Myers, OSU's Baggett Frazier professor of vegetable breeding and graduate students Carl Jones and Peter Mes.  The genes involved in producing the OSU Blue tomato are Aubergine (Abg), Anthocyanin fruit tomato (Aft) and atroviolaceae (atv), these genes came from the wild species Solanum lycopersicoides, S chilense, S cheesemanii, respectively.

This means that, just like every other domestic tomato, the OSU Blue is a complex yet stable hybrid.  I am happy to say that this is a very stable hybrid just like many other types of tomato and seeds are simple to save and they grow true to type.  Being derived from the wild tomato species I had hoped it would be resistant to a bunch of diseases, at this stage I don't know if it is or not.

On a side note I rather like S cheesemanii but they are as rare as hen's teeth in Australia, if you happen to be growing any please talk to me as I would love to get some seeds from you.

The anthocyanin is the same colour that is in eggplants and it is a rich antioxidant.  The fruit ripens to a dark blue/purple/black colour wherever sunlight hits it, anywhere the light does not hit ripens red.  If a leaf or calyx or whatever is on the fruit it gets a shadow of red.  If you were to put a sticker on the unripe fruit it remains red underneath allowing for all sorts of sillyness such as spelling out the names of your kids one letter per tomato.
OSU Blue Tomato, not overly large
 The plants grow and look much like any other tomato plant.  They are indeterminate and grow a regular leaf, the flowers are yellow and much the same as any other tomato.  The leaves and stems may take on a little purple colour if the temperatures are low and the light intensity is high.  When the days get too hot the plant does not colour up as much.  The fruit takes on more colour with low temperatures and high intensity light.  People who grow these to sell seeds on Ebay and such use grow lights to get the fruit to take on more dark colour.  The colour seems to be variable even on the same plant, my plants grew a range of dark to super dark fruits.

The fruit are small, but not too small, about 4cm across.  The dark colour is mainly concentrated in the skin and a little in the flesh just under the skin.  The flesh remains red and the seeds look much like any other tomato seeds.
OSU Blue Tomato
OSU Blue with some skin removed
One question I get about the OSU Blue tomato is about the taste.  If you read about any of the high anthocyanin tomatoes on the Oregon State University web page they sound like they taste absolutely terrible.  In reality they taste ok,  certainly not the greatest tasting nor the worst tasting.  If I had to choose one word to describe the taste it would be "underwhelming".

They tasted slightly better than an average store bought tomato.  Tomatoes from the shops are pretty dreadful at the best of times so this is not a glowing review.  If you are expecting a great tasting tomato because it is home grown then you will be disappointed, other than that they are ok.  It does taste better than other tomatoes I have grown such as apollo (or possibly roma) so are not all that bad.

They lacked any real depth of flavour, they were not very sweet and were not very sour.  They were not overly insipid which was a positive, but they really didn't make a memorable impression on my taste wise.  I have certainly eaten a lot worse tasting tomatoes.
Unripe OSU Blue tomatoes
The blue colour starts long before the fruit is ripe, the unripe tomatoes look very nice while you wait for them to ripen and become edible.  The plant itself is nothing spectacular, it does not crop all that heavily and is not overly robust.  That being said it was not a weak plant and did return a reasonable yield in far less than ideal conditions.
OSU Blue tomato in Australia

I saved a reasonable amount of seed from my plants and do plan on growing this variety again.  I have a few breeding plans and would love to incorporate the colour into a better tasting, higher yielding variety.  I have seen some people use this to breed a great tasting tomato that has the black/blue skin but is yellow on the inside, I have also read about someone who grew tomatoes that were red and had dark stripes like a tiger.  Lots of fun.  There are many options and I only have so much space/time to pursue them.  We will be moving to town  shortly so I may not be allowed to grow many vegetables for a while.

I have also been asked how OSU Blue Tomatoes got into Australia.  I have no idea how this variety found its way to Australia, it was bred after they closed the doors on the importation of tomato seeds.  Perhaps a university or the CSIRO imported them legally and they leaked out from there, perhaps some private grower or a sneaky large seed company imported them on the sly and was able to evade quarantine (please do not try this).  Perhaps someone or some company payed a small fortune to get the right tests done in order to legally import them.  The person who I got the seeds from initially received them unsolicited from another grower and asked no questions.

I guess I will never know how they got into the country, I also don't particularly care.  Now that they are here I can grow them, distribute them and use them in all kinds of tomato breeding projects.

OSU Blue Tomato seeds for sale in Australia
I may sell OSU Blue tomato seeds, and/or I may breed some new type of high anthocyanin tomato and sell its seeds.  If I do they will be listed on my for sale page along with other annual and perennial vegetables that I sell in Australia.


  1. Hi do you still sell plants via mail if so how does one purchase thanks

  2. Hello,

    we are currently in the process of moving house so unfortunately I am unable to sell plants through the mail for a while. I am guessing it may take a while until I am able to do so again. I will update my For Sale page when we are settled in

  3. How do I follow your blog I can't seem to find a button

    1. Hi RJP,

      If you look on the right hand side just above the list of followers there should be a button that says something about "Subscribe to Mudflower". I think that does it.