Blossom-End Rot and Synthetic Fertilizers: Back to the Basics

I received this question via email late last week, and after doing some research, think that it will be very useful to those who have planted tomatoes and/or peppers, especially at this point in the season. Wanted to pass along what I found!

Brad Guindon writes:

Hi, I am a friend and follower of ECC and the garden blog. I started a mini patio garden this summer at my apartment west of St. Louis where I live. I have red peppers, zucchini and basil growing in one large container, and an upside-down tomato plant hanging by my front door. Everything has been growing great until recently. The pepper, which is green and about the size of a golf ball, probably a little bigger, has recently had a soft brown spot appear on a decent sized area of the pepper. I have been making sure to keep then well watered, especially recently with the high temperatures here. I have attached a blurry picture to help with your diagnosis. If you can, please help save my pepper!

Hi Brad!

Thanks for your question, and for following the blog! I did some research based on your description and ran the picture by my dad, and it looks like you are dealing with blossom-end rot. This is a calcium deficiency that causes the dry, sunken spots that you noticed. It is typically found on the first few fruits, and is evidence of fluctuations in the soil saturation and an irregular uptake of nutrients. It is likely that despite your noble efforts to keep the vegetables well-watered, that the high temperatures caused some inconsistencies.

Most of my suggestions are more preventive than anything:

• First off, next year I wouldn't put too many different vegetables in one pot. It often surprises people to learn just how much soil you need even for one plant, and with too many different varieties you will find that they compete for nutrients in the soil.
• Also, avoid using water soluble fertilizers (like Miracle Grow). These do not stay in the soil profile long and usually contain a higher concentration of synthetic nitrogen (synthetic releases too quickly to regulate the uptake of nutrients and leaches out of the soil--abetting nutrient deficiencies and thus problems like blossom-end rot). I would steer you more toward granular/organic fertilizers to help regulate the nutrient uptake. For more information on synthetic nitrogen, check out the Northeast Organic Farming Association article HERE. For general information on organic vs. inorganic check out a post from the Vegetable Gardener HERE. And if you need any help in selecting an organic fertilizer, just stop in to Swindlers and check out our selection of Espoma organic fertilizers and plant food!
• Make sure your pot has good drainage, and maintain a very consistent watering schedule.
  
• And to ward off blossom end rot in future gardens, you might try putting down some calcium nitrate about the time the plants start to blossom. The guys over at Wilmington College used calcium nitrate this year for this very purpose.

And for this year's garden there is good news. Discard the affected fruit and try out some of the above suggestions! Let me know if you are successful in saving the peppers!

Oh, and HERE is a link to an OSU extension fact sheet that I found useful (don't get too freaked though, they make it sound pretty ominous).

In fact, here is a sample picture they have included of a pepper affected by blossom-end rot:

Hope this information is useful to you as the season continues!