Tomato problems

Jill Severn

Just when everything in local vegetable gardens was at a peak of bounty, trouble struck a friend’s tomato crop: The dreaded blossom end rot. That sent me on a little Google research expedition, and back to Gary Ritchie’s excellent book “Inside Plants.”

On that research expedition, I found myself exploring all manner of tomato maladies. If you read all the fact sheets about creepy fungal diseases, marauding insects and damage from environmental factors, you’d wonder how any of us has healthy tomatoes.

That expedition reminded me of reading online medical information when you have a cough, and becoming convinced that you are dying from some terrible disease.

For instance, I discovered that some of my own tomatoes have an ailment called sun scald. The affected tomatoes are actually quite pretty: their shoulders stay a lovely shade of orange. I had thought that was because they weren’t quite ripe. Learning this was a problem scared me for a bit, until I realized that mostly, they’re fine inside their sunburned skin. Only one of ten was unhealthy looking under that glowing orange.

That was a relief. It seems reasonable to assume that September weather will stop sunscald, so I felt no need to read any more about it.

Still, that made me wonder: Since tomatoes are not fond of days over 90 degrees, and we are having more of them, maybe our gardens will need patio umbrellas next year for some afternoon shade. Then I met some gardeners who are already experimenting with ways to shield their plants from the hot sun with various kinds of shade fabric, umbrellas and even tarps.

Blossom end rot, however, is a serious problem, and it’s a complex and science-y one. It’s usually caused by a deficit of calcium. Gary Ritchie’s book notes that: “Calcium is immobile in soil and very immobile in the plant. Hence, once calcium has been taken up it moves painfully slowly.” Other causes are too much nitrogen, irregular watering, cold soil, the wrong pH level in soil, or root damage. We certainly know our soil isn’t cold, and if we haven’t kept our tomatoes consistently watered we can’t go back in time to fix that. Nor is there a way to remove nitrogen from our dirt.

So, executive summary: There’s no quick fix.

Your best hope is to prevent blossom end rot in next year’s crops of tomatoes – and also in peppers and squash. Usually that means choosing one of several ways to add calcium to your soil, and maybe checking your pH with a little meter you can buy for that purpose. For most crops, it should be about 6.5; for a few, like potatoes and strawberries, it should be lower – that is to say, more acidic.

Those of us who add a little bone meal and a little wood ash to our soil every spring (along with big helpings of compost and/or manure) are usually spared from blossom end rot; that’s been the case for me. As in all of life, it’s about balance.

Other sources of calcium are egg, oyster and clam shells (which take a very, very long time to break down), dolomite lime (which raises soil Ph), and gypsum or calcium nitrate, which are a mystery to me. Clearly, I should have taken chemistry in high school.

Here’s a true confession: At this late date, I’m not even going to try to learn chemistry. There are limits to my curiosity. I’d like to know more about a lot of things, but I’m willing to let scientists claim dominion over the chemistry of the world. I will take their advice on what to put in my soil, as long as it’s simple, sustainable and sensible. Because they know a lot, the mass of us gardeners can get by knowing a little.

That’s why we owe Gary Ritchie a debt of gratitude for mastering the amazing complexity plant anatomy and physiology. His book teaches us to appreciate that complexity, even if we never fully understand it. And he tells us what to pay attention to, and how prevent or solve our garden problems.

No matter how long any of us has been gardening, we always have more to learn, but thank heaven we can get by without learning everything.

Jill Severn writes from her home in Olympia, where she grows vegetables, flowers, and a small flock of chickens. She loves conversation among gardeners. Start one by emailing her at  jill@theJOLTnews.com