During my visit to the Minnesota State Fair, I had a chance to chat with the Minnesota Master Gardeners staffing the extension booth in the Horticulture Building. I asked what was the most frequent question they were getting at the fair. The answer: Why do my tomatoes look so bad? Many gardeners (including yours truly) are experiencing blossom-end rot on their tomatoes.
According to the Master Gardeners, fluctuations in moisture and too much fertilizer are the most likely causes of blossom-end rot. “Tomatoes don’t like too much nitrogen,” one of the MGs reminded me. I’m seeing blossom-end rot mostly on my paste tomatoes, which are in a new bed to which I added lots of compost. (Oops.) For best results with tomatoes, don’t grow them in the same place more than once every three years. Interestingly, my best-performing tomatoes are yellow pears, growing in a mixed bed in which I have never grown tomatoes.