Grafted Tomatoes: The Jury Has Reached a Verdict

THIS is a thing of beauty....the Black Krim tomato.  

The deep red-purple, almost black, green-shouldered variety of tomatoes known as 

"Black Krim" (Solanum lycopersicum) originated in Krim, Russia, near the Black Sea. 

This open-pollinated tomato is indeterminate, growing on 4- to 7-foot vines and producing numerous 

6- to 12-ounce globe-shaped fruits. Fans of the "Black Krim" rave 

about the rich, salty flavor of its fruits, and have compared it to a fine, single malt scotch, 

according to Amy Goldman, author of The Heirloom Tomato.

Here are my grafted Black Krims in the test greenhouse, almost touching the ceiling. 

Guess I'm sporting the 'Bob Dole' pose to keep my arm out of the tomato jungle.

Anyway.  

The Black Krim is a particular favorite.  Our friends at

Baker Creek Seeds sponsored and paid for a study of the most nutritious 

tomatoes by variety.  Black Krim won for highest Vitamin A content, 

second highest lycopene content, and a Brix of 7.82! 

Chart Courtesy of Baker Creek Heirloom Seeds and Wild Boar Farms

Vitamin A is good for your eyes, boosts your immune system, can help neutralize free radicals in your system.  Lycopene benefits your blood vessels, is a powerful antioxidant, and has proven

to reduce prostate cancer risk.  The study funded by Baker Creek confirmed that 

Black Krim tomatoes have 3 TIMES the Vitamin A and 4 TIMES the lycopene of

a vine ripened hybrid tomato.

But, what is a Brix measurement and what does it tell us?

Big and prolific plants are just one benefit of grafting.

Degrees Brix (symbol °Bx) is the sugar content of an aqueous solution.

In other words, the higher the Brix value, the sweeter the tomato.

If you're interested, you can buy inexpensive Brix refractometers on the internet if you'd

like to measure the Brix level of your own vegetables.

A high Brix reading (each fruit and vegetable has a different Brix range) 

indicates the fruit came from a successful plant and that the gardener has soil, water, 

air and sun working together optimally.

The plant uses glucose as a building block, so if your tomato has a high Brix reading, 

it has more of everything, especially taste. 

A Black Krim has more of everything to start out with when compared to a hybrid.  But, 

you can grow any tomato in less-than-optimum conditions and not get the great taste.

So, get to the grafting part already, right?

You can read a lot about grafted tomatoes, and some sources will sing praises and promise yields over and above what you would normally expect.  Other sources will poo-poo the concept and say

the overall yield wasn't impressive enough to warrant the extra propagation work.

I SAY

I grew a greenhouse full of grafted tomatoes this summer, and

the fruit set was quite a bit higher, but not wow-out-of-this-world-crazy fruit production 

like some of the ads from some catalogs will suggest.

What DID impress me was the disease resistance of the grafted heirloom plants.

Especially this year, when the nights were too cool for things to grow at a normal rate.  

We all also know that cool nights provide the perfect environment for disease.

 Late summer Black and Brown Boar, grafted to disease-resistant rootstock.

 Late summer Black and Brown Boar, ungrafted, succombing to 

gray mold in the greenhouse.

These two photos were taken on the same day.  The plants were planted the same day, in the same greenhouse, using the same seeds for a somewhat controlled experiment.

It's more than obvious that the 

grafted plant looks healthier, and I wonder if you did a Brix reading, which 

fruit would have a higher sugar content?

These two photos are of an heirloom variety called "Jaune Flamme".  The top photo, as you may have already guessed, is the grafted plant.  The second photo is the non-grafted plant.  It, too, is 

displaying evidence of gray mold, where the grafted plant is not.

A couple more shots of grafted Roma tomatoes in the test garden this year.

So, this jury of one has reached a verdict.  

Not only can you get more fruit on a grafted plant, 

you also get the great flavor of an heirloom variety and increased nutritional-value fruit

 on a disease-resistant plant.  This becomes particularly more important if you 

happen to be growing in an area with a short growing season.

By practicing good soil stewardship and caring for your soil, by increasing the organic content of your garden soil and feeding the microbes in your soil, 

you are also elevating Brix levels and getting tastier tomatoes.  

Grafted plants yield more of those tasty 'maters for a win-win situation.

So, if you're not already, start composting and add it to your garden soil!  

(A note:  do NOT compost diseased plant materials.  Dispose of them promptly.)

We are also composing the information and photos for an upcoming post on 'green manure', 

and cover crops, featuring the buckwheat that is 

currently growing in the high tunnel and info from the U of Minnesota seminar we 

attended last month.

After this year's test garden, we will definitively have grafted tomatoes next season, 

with a wider selection of heirlooms, not just the Black Krims.  

Did you buy a grafted tomato this spring?  What was your experience?
Feel free to let us know what your take was on the Black Krims in the comment section.

Happy Gardening,
Kathy and Patty