I have been growing peppers this summer and they have been doing great. The fruit is really starting to take off, but now I have 3 or 4 of my larger fruit getting these brown spots. This is a Red Marconi pepper. Can anyone give me any guidance on what to do to alleviate this problem. I have done some research and found that it might be some type of fruit rot, but I am not sure what to do help it if it is. I am concerned this could spread to my Bhut Jolokia or Red Thai which are next to these if it is some sort of disease.

These plants are being grown in a pot and I have been feeding them some miracle grow for vegetables maybe once every 2 weeks. The pot is not over watered.

Brown Spot 1

Brown Spot 2

  • It might not be your case, but my red bell peppers had the same tanned blotches where the sun was shining the strongest. The peppers were getting seared by the sun. I ended up wrapping the peppers in white paper to block the sun from the peppers, but still allow the leaves to photosynthesize. Your base might be different in that the blotches are not on the outer perimeter of the whole plant.
    – JoJo
    Commented Aug 25, 2015 at 6:23

4 Answers 4


I would have said Blossom End Rot because that seems to be the most rot along these lines., and especially as you have it on a few of the larger fruit. It is caused by a Calcium deficiency. Check your MiracleGro - it is probably almost all NPK but might have Calcium in smaller quantities. Is that enough? I don't know.

Usually the problem occurs more due to a mobility problem with the Calcium when watering is erratic - yes the plant might get water, but it might go a couple of days without water and then get it all at once. I have seen this and is probably hard to avoid with modern drought restrictions.

Ohio State have a Blossom End Rot Fact Sheet that is worth reading. As well as lack of Ca in the soil, and erratic watering, they mention "competitive cations". What they mean is the pepper plant is absorbing similar ions to Calcium instead of Calcium - and then has a lack of calcium in the fruit. They mention ammonium specifically, but magnesium is probably a candidate (it is common, and is chemically very similar). Check your MiracleGro - if it is ammonium based, them this could be your cause. OSU's recommendations are:

  1. Maintain the soil pH around 6.5. Liming will supply calcium and will increase the ratio of calcium ions to other competitive ions in the soil.

  2. Use nitrate nitrogen as the fertilizer nitrogen source. Ammoniacal nitrogen may increase blossom-end rot as excess ammonium ions reduce calcium uptake. Avoid over-fertilization as side dressings during early fruiting, especially with ammoniacal forms of nitrogen.

  3. Avoid drought stress and wide fluctuations in soil moisture by using mulches and/or irrigation. Plants generally need about one inch of moisture per week from rain or irrigation for proper growth and development.

  4. Foliar applications of calcium, which are often advocated, are of little value because of poor absorption and movement to fruit where it is needed.

When I've seen it, watering has been the main issue during drought conditions. Rot has not been too widespread. Pick the fruit before the rot gets too big. You can still eat it - just cut the rot off. If you wait too long, the rot will spread (secondary infections have taken over) and there's nothing worth saving.

  • Yes, look at the leaf droop in the first picture - they look underwatered. Someone seeing this "rot" for the first time would think it a symptom of overwatering, and go the wrong way - @Mike's last line "The pot is not overwatered" makes me think he may have fallen for that.
    – Ed Staub
    Commented Jul 19, 2012 at 13:00
  • Great post. Thank you so much for the information. I think one of the problems is that the pot they are in is getting too small, so the peppers use all the water in there too fast for me to get them more water. I will look at the miracle grow I am using and see if it has enough of the nutrients you recommend. Again thanks for a great post.
    – Mike
    Commented Jul 19, 2012 at 14:58
  • Great question/answer. I was having the same problems with mine; watering being erratic lines up exactly with us. Hard to deal with when its 100+ outside and our water district only allows 2 days a week of automatic watering.
    – Kellenjb
    Commented Jul 21, 2012 at 18:23
  • So I finally got around to making some of these changes. I added calcium and a 5-10-5 fertilizer along with transplanting them to a bigger pot. I will update again when I see any changes. One followup question too. Should I remove the ones that are showing the spots or let them be?
    – Mike
    Commented Jul 24, 2012 at 17:53
  • I would probably remove them. The rot is only going to get bigger, so you might as well salvage half a pepper. Also mature fruit on a plant will tend to subdue the formation of more fruit.
    – winwaed
    Commented Jul 25, 2012 at 19:11

The pot looks small. It could be root bound. Any flowering/fruit bearing plant taller than 2 feet should get at least a minimum 5 gallon pot. 2 feet of above soil growth = minimum 5+ gallon pot. Roots need room to grow to allow for enough surface area. More root growth=more surface area= more nutrient absorption= healthier plants and more fruit. Ca deficiency can also be a by-product of root bound plants.


I have the same problem. The nursery told me to put some Lime in the soil. A second gardener recommended "Lilly Miller,"Super Sweet". I have removed the peppers that have the Calcium problem and hopefully this will help.


A few years late, but more consistent with anthracnose.


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