The Great Tomato Debate

Some of you may have noticed a new kind of tomato began to appear on the shelves of

Nurseries in the spring of 2010.  These are grafted varieties.  Grafting is a method of growing the top of a plant (the scion) onto the rootstock of another plant.  It is done to achieve hardiness, manage the size of a plant, increase production and disease resistance.  In the 19th century the wine industry in France was saved from devastation by phylloxera by grafting grapes on to disease resistant rootstock.  Dwarf fruit trees are often grafted onto different rootstock to ensure their size will be small.

With those successes in mind, a local grower, Log House Plants, began introducing grafted tomatoes into the retail market.  This year, they hit pay dirt.  The plants flew off the retailers’ shelves even though they carried a hefty price tag — three times the cost of a regular tomato.

After a year of standing by, watching the action, fielding questions from clients and talking to people in the nursery business, I have to admit I was as curious as I was skeptical.  So, I set up my own less than clinical but credible experiment.  I bought two tomato plants of the same variety, an heirloom tomato named “Brandywine”, one grafted and the other non-grafted.  I planted them side by side in an amended bed with the same exposure to sun and the same watering patterns and stood back and waited…

A bit of background would be handy here:  Heirloom tomatoes typically bare fewer tomatoes than their other contemporary hybridized cousins.  So grafting heirloom varieties could be a really fine idea if one of the outcomes was more luscious fruit.  The other point of interest was the claim by the grower that this method can extend growing time because the wild rootstock the plant is grafted to is significantly more robust and cold hardy.  Well, that got my attention since we live in the Pacific Northwest where we are starting to count our summers in days instead of months!

The harvest mostly in, the votes counted and the findings are:

  • When I finally did harvest a ripe tomato, it came from the un-grafted plant.  The grafted plant had significantly more fruit but the FIRST tomato, the one we all wait for, came from the “Plain Jane”.
  • The grafted plant was about (remember this is not a clinical study) 20% bigger and fuller than the non-grafted tomato which is both a blessing and a curse because current grooming protocol calls for pruning the side shoots (the unproductive greenery) from tomatoes to focus the plants on fruit not leaf production.  This meant I spent at least 20% more time pruning the grafted plant and frankly in early September, I gave up keeping up.
  • The sizes of fruit from the grafted tomato were all approximately 30% bigger than those from the regular Brandywine with thinner skin.  The color of the fruit was pinker and lighter, not the red/orange of the “regular” Brandywine.
  • But, here’s the most important outcome…taste.  Taste testing the fruit with a few brave gourmands, picked simultaneously and hauled into the kitchen and eaten without accompaniment, the non-grafted Brandywine tomato won hands down.  TA DA!  The grafted Brandywine’s taste was diluted and watery in comparison.  It lacked that wee bit of acidity we all crave in a fresh, sun warmed tomato and the texture in contrast, was mushy.

There you have it.  Grafted Tomatoes are larger and more robust but the crop they produce pales in comparison to the non-grafted tomato in the taste test and will cost you three times more.

So…Why bother?  Next year save your money or spend it on a few more regular, old, non-grafted, tried and true tomatoes with exotic names like Green Zebra or Black Krim.  Take a bite out of a tomato, not your wallet.