Tomatoes are the number one vegetable grown in gardens and container gardens.  And this time of the year, although there are many tomato questions, the most common one is this…”The bottoms of my tomatoes are turning black!  What’s that all about?”

   It’s a very common problem on tomatoes (can also happen on peppers, squash, melons, and eggplant), and it’s called Blossom End Rot.  It can be the result of many factors including uneven soil moisture, young plants trying to become rooted and established and yet produce new growth and fruit at the same time, high feedings of Nitrogen, and a lack of calcium in the fruit. 

   So, how do you combat Blossom End Rot right now?  The first and most important step is to make sure the plant has good even soil moisture at all times.  Increase timely waterings, and mulch tomatoes growing in the ground to help retain soil moisture.  Even moisture is the most important first step in reducing Blossom End Rot.

   Add calcium in the soil.  Lime or gypsum will take care of that, and make sure your fertilizer has calcium in it as well.  Blossom End Rot may be more of a problem in containers, as potting mixes do not contain calcium, and are sometimes harder to keep evenly moist. 

   And don’t over feeding the plants, especially with a high nitrogen fertilizer.  Excessive growth, stimulated by the high Nitrogen, increases excessive foliage production, which increases the need for water and calcium to the leaves, and results in the lack of moisture and calcium to the fruits.  Use an all-purpose garden food, which is lower in N and higher in Potassium and phosphorus, as well as calcium.

   This very common tomato problem typically becomes less of a problem as the season progresses.  Remember it’s a physical problem, not a disease, and tomatoes affected by blossom end rot can still be eaten.  Simply slice off the darken area on the bottom.  Do what we’ve recommended, be patient, and the Blossom end rot will go away on your future fruits.  Then your tomatoes will be just right for the squirrels to take a bite out of them!.