This year a majority of our tomatoes have brown spots on the bottom. Some of them as soon as they are ripe they have mold growing on them. Are these safe to eat an can or what do I need to do. We have about 8 or 9 plants. They are not producing that well. It seems to be on all of are tomatoes except for the grape. What can we do to get this problem taken care of?



  The dark sunken area on the bottom of tomatoes is called blossom end rot.  This is caused from a calcium deficiency in the fruit.  There is no need however to add calcium to the soil, there is an abundant amount of calcium in our soils.  Because calcium is carried up the plant with the water, the problem usually manifests itself when there are fluctuations in watering (too wet à too dry).  Using a mulch layer around the base of your tomatoes will help remedy the problem.  Water the tomato plants deeply and as infrequently as possible.  Some varieties of tomatoes are also more prone to get blossom end rot than others.  One more thing to keep in mind is that during extreme environmental conditions, the “first fruits” of almost all varieties will show these symptoms but then the subsequent fruits will be fine.  You can still use the tomatoes, just remove the darkened area.  For more information on growing tomatoes check out the USU Fact Sheet at http://extension.usu.edu/files/publications/factsheet/HG_2004-05.pdf.

Posted on 6 Aug 2008

Jaydee Gunnell
Master Gardner and Horticulture Agent, Davis County

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