Avoiding a common pitfall with tomato plants

You’ve planted your tomato starts in a nice sunny area and supplemented them with water and fertilizer.  Provided weather remains warm and hail free, your vines should produce a bumper crop of red beauties 52-70 days from the time the blossom sets.  Right? 

We hope that this scenario will be true for you.  After all, there is nothing like the taste of a home-grown, fresh-from-the-vine tomato.  They are by far the most popular vegetable plant we sell. 

Unfortunately though, late summer can bring a few surprises.  One of the most common problems encountered is blossom end rot.  It appears as a sunken dark spot on the bottom of the fruit.  Unlike diseases, it is not transmitted from plant to plant or even from fruit to fruit.  In fact, this problem is completely caused by environmental factors.  So, the good news is, you can prevent the problem. 

First we’ll address causes.  In Short, if your tomato vine cannot take up water or calcium properly, the fruit begins to rot.  Contributors can include:  allowing the plant to go too dry during active growth, planting too early in cold soil (usually only the first fruits are affected in this case), or keeping the plant very wet (such as in clay soil) where root development and therefore H2O and calcium uptake are inefficient.  Use of a fertilizer that is high in nitrogen can also contribute to this deformity. 

So it is important to keep moisture levels consistent especially during hot dry spells or when tomatoes are grown in containers where moisture can fluctuate a great deal.  Make sure your soil is well-drained since waterlogged soil will cause weak root development.  Plant when the soil is warm (or use a ‘Wall O’ Water’ to warm the soil for an early planting).  Lastly, use fertilizer that is relatively weak in nitrogen. 

A spry for blossom end rot with the active ingredient calcium chloride is also available.  You can use this as a preventive spray on developing fruit.  If you use it to treat plants with an existing problem, you will first need to prune off any fruit that have blossom end rot as the spray is a preventative and will not take away the rot from already affected fruit.

For any questions you have on this article, or any topic of concern, email us—or better yet, come by and talk to one of our professional staff members.  Remember, Phelan Gardens is open year-round!   

For additional information, check the following links:

• Recognizing Tomato Problems
• Tomato diseases