June 25, 2012

Garden Fail: Blossom End Rot

And now the answer to the question, "Why do you plant so many tomatoes, Saskia?" Because I know that a percentage of them will be affected by problems such as blossom end rot--pictured below--pests, leaf roll, cool weather and other issues that might reduce my harvest. And since one can never have too many fresh tomatoes in the summer, I plant loads of them. In the event of a totally problem-free season (hasn't happened yet), I will enjoy preserving the bumper crop.

Striped Roman tomato suffering from blossom end rot

The extra plants are a kind of insurance, and it turns out the insurance will be important this year. As of this morning, almost every one of the twenty plus tomato plants in my yard was filled with half-rotten tomatoes afflicted with blossom end rot. I pulled half a bucket full of them from the vines and tossed them in the compost pile.

Blossom end bummer

Blossom end rot is a physiological disease involving calcium deficiency that is caused primarily by fluctuations in soil moisture content. In other words, it's not caused by some outside bacteria, virus or pest, and I could have prevented it with more careful attention to watering. For tomato plants growing directly in the Davis clay soil, a deep watering once every 7-10 days should suffice; I got busy/lazy and let my plants go two weeks without water at least twice in May, so I guess I kind of asked for this!

In my experience, blossom end rot happens more often toward the beginning of the season (now), and it happens more with certain varieties than others (Roma types, for example). I'm sure there are products on the market designed to combat this problem, but I know it will resolve itself as the season progresses, as long as I do a better job of monitoring my watering.

Because blossom end rot starts at the base of the tomato, you might not notice it as the tomatoes are developing. For example, these tomatoes look perfectly happy from where I'm standing, above them:

Pretty looking tomatoes

But flip them up and you get a nasty surprise: the entire base is rotten:

Extreme blossom end rot

A few years ago I might have sat down on the grass and shed a tear or two at this development, as disappointing as it is, but now I understand that being a farmer means enduring failures like these on a regular basis (except I bet real tomato farmers don't deal with this particular type of failure very often, as they have enough experience to know how to prevent it.) After picking all the rotten fruit off the plants this afternoon, I stopped to give thanks for the unaffected fruit that was still hanging on the branches and for the loads of ripe cherry tomatoes, none of which were affected for some reason. I also resolved to be more consistent about watering.

Super Sweet 100 cherry tomatoes

To help alleviate the disappointment, I picked a bouquet of Becky Daisies for the dining room table. They are so beautiful, it's as if the garden is saying, "Hey, don't worry about it! Enjoy these gorgeous flowers instead." 

A vase full of happiness

How do your tomatoes look this year? Is blossom end rot a minor issue for you, or have you dealt with entire plants full of ugly-bottomed fruit? Or are you all much more disciplined than I am about watering and therefore don't have this problem? (On second thought, if that describes you, I don't want to know about it!)


  1. I certainly felt your pain last year as more than a few of our toms were afflicted with end-rot. So far, so good this season.

    Your plan of planting more and different varieties for insurance purposes is a wise one, especially these last few years when summer temps are not always consistent. Some varieties love the raging heat; others, less so. Be gladdened by what you get, and learn from the mistakes to be even more gladdened next year.

    You have kindred and sympathetic spirits growing in Citrus Heights.

    Rachel and Anthony of thecookhousegarden.

    1. Glad to hear I'm not the only one! Some of my tomatoes are directly in the Davis hard clay soil, and others are in raised beds that drain quickly, so that complicates the watering, too.

      Hope you and your son are doing well, and that you're enjoying your summer garden!