Question
I live on a ranch in northeastern Wyoming, USA. I have had trouble with blossom end rot on my tomatoes since we put in a new water well several years ago.  I have moved the tomato area, and used different soils, such as potting soil or native soil with no change.  The only constant is the water.  The water has high total dissolved solids, high Electrical conductivity, low sodium absorption ratio, but high nitrates. I understand from research that blossom end rot is due to a calcium deficit.  My question is could the nitrates in the water be tying up the calcium in the soil, and if so what could I add to the soil to counteract this condition?  Is it possible to add calcium in powder form to the soil?  I am adding calcium to the water right now with limited success.

Answer
Nancy, you are correct that the problem is a lack of calcium. But often, that does not necessarily equate to a lack of calcium in the soil. Instead, the problem is usually caused by the plant's inability to properly absorb the nutrients needed for proper growth and development. This is especially true with tomatoes and peppers during the first month after transplanting.

I have found that adding two tbs. of epsom salts to the soil (tilled and mixed well) when transplanting usually minimizes this problem. I have also found that adding a high concentration of organic materials such as aged manure, peat, and compost, is also beneficial.

The problem is that this condition is spurred by several factors, including weather, native soil, and the particular variety you are planting (some are more susceptible than others). Any of these variables alone or in combination can stress the plant after transplanting, which is why most of the blossom-end rot problems occur with the first flush of fruit.

My recommendation is to try a more hardy variety such as Better Boy or any of today's disease resistant hybrids. Many catalogs list which diseases and conditions they are resistant to. Also, supplement your soil with the organic amendments I've listed above.

I would also add the epsom salts when planting, and spray the plants with a mix of 3 tsp. of epsom salts per gallon of water for the first month once every seven days. I am not a chemist, but it has been proven that epsom salts aid the plant in its ability to absorb nutrients. Finally, mulch the plants with straw or shredded leaves to cool the soil, retain moisture, and reduce stress.

I hope this answered your question. Please write again if I can ever be of assistance.

Regards,

Mike