Jun 142014
Blossom End Rot and What To Do

When the fruit first begins to form in your vegetable garden you may notice a condition where the blossom ends of the fruit turns brown to black then begins to rot away. This can happen to a number of different vegetable garden producers like tomatoes, squash, peppers, and more. Aptly named “Blossom End Rot”, this condition is nothing to be overly concerned about. It’s disappointing to see something you’ve been eagerly awaiting for weeks get seemingly ruined – but it is only temporary!

Blossom End Rot on Summer Squash


What Causes Blossom End Rot?

Blossom end rot is a calcium deficiency that prevents the proper formation of cells in the fruit. Just like people, plants need nutrients like calcium for proper growth. The calcium deficiency can be cause by a couple things but is usually an issue with too much water not allowing the plant to bring in calcium through its root system. You will see blossom end rot mostly at the beginning of the plant’s fruit production when the spring rains have been fairly frequent and soils tend to be saturated with water.


How Should You Treat Blossom End Rot?

The first instinct anyone has with any problem is to DO SOMETHING but it probably isn’t necessary. Many people will tell you to add nutrients to the soil to fix it. Usually when you do this the next set of fruit is fine but it isn’t because you added anything to the soil – the plant would have corrected itself when the water and soil conditions improved. In most soils there is plenty of calcium for plants to use. At the beginning of the season plants may not be able to bring in enough calcium due to frequent rains or over watering creating and oversaturated soil situation which prevents the uptake of nutrients and causes the blossom end rot. Simply correcting the watering situation is usually all that needs done! Dispose of the fruit as soon as the rot begins to form so that the plant doesn’t waste time and energy on producing useless fruit.
Often you’ll see tips like adding bonemeal or lime to the soil. You might also have been recommended to fill a newly emptied milk jug with water and water the plants with the milk-water or even add tums. I’ve done these corrective measures too and the result is pretty much the same: the first set of fruit has blossom end rot but the second set is perfectly fine. Sometimes it is hard to do nothing and just wait on things to get better (being patient can be hard!) Think of it like a doctor prescribing antibiotics for a virus that will run its course in 3-5 days and the doctor tells you that you’ll be better in 3-5 days. It may make you feel better to do something but it really wasn’t going to help.

If blossom end rot persists throughout the season then you may need to add something to the soil. If this is the case have your soil tested to see exactly how much and what the extension services in your area recommend.

Have you seen blossom end rot on your plants this year?


Dave has written GrowingTheHomeGarden.com since 2007. He gardens on an acre and a half where he raises his 5 children. He enjoys growing vegetables, herbs, and propagating plants. Dave works as a real estate agent in Spring Hill, TN.

Reader Comments

  1. My squash hasn't a chance anyway in the desert heat in El Paso. Once June arrives the thin mountain air makes el sol a blowtorch on plants! But just wondering, too, if you could draw the same "blossom end rot" analogy on what's happened to my Star Jasmine and Honeysuckle vine blossoms? I've even built them some arbor shade. Bloomed prolifically during April and May, and then once that heat hit it looked like they went into an immediate retreat. Wilty, much of the vines turning brown, dead; and all those beautiful blooms shriveling to a blackened end. Could this be because I've watered too much during the spring? We sure don't get enough rain to amount to anything here! Thanks.

    1. Hi Dan,

      Interesting question but I think it may be more related to the plant just becoming too dry with the adverse weather conditions. I suspect the intense heat you describe contributes to a massive decline for your Jasmine and Honeysuckle rather than an issue involving too much watering in the spring.

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