What To Do When You See Blossom-End Rot
Do your tomatoes look as if they are rotting from the bottom up? The culprit is probably blossom-end rot! This frustrating problem can appear to come out of nowhere. Here are top tips for preventing blossom-end rot on your tomatoes and other garden plants.
What Is Blossom-End Rot?
Are your tomatoes developing a dark, sunken spot on their bottoms? Unfortunately, they likely have blossom-end rot. It’s a common problem for fruiting garden plants such as tomatoes, peppers, eggplants, and squash. Blossom-end rot is a disorder in which the tissue of the blossom end (the “bottom”) of the fruit breaks down and rots, thus reducing the quality of the fruit and the overall yield from the plant.
What Causes Blossom-End Rot?
Thankfully, blossom-end rot isn’t caused by a disease or pest. Instead, it is the result of a lack of calcium in the plant. This lack of calcium may be due to low calcium levels in the soil or—more often—soil that is over- or underwatered. Wide fluctuations in soil moisture reduce the plant’s ability to take up calcium from the soil. When the demand for calcium exceeds the supply, the tissues in the fruit break down, and blossom-end rot occurs.
In addition to watering issues, calcium deficiency during fruit formation may also be caused by:
- Too much nitrogen-heavy fertilizer
- Improper soil pH
- High salt levels in the soil
- Damage to plants’ roots
Awareness of these causes when caring for tomatoes and other garden plants is the best way to prevent blossom-end rot.
Some blossom-end rot is more or less normal in the first tomatoes of the season since the plants are usually under stress during the initial fruit set. It also tends to happen more often in plants grown in containers, as the soil is more susceptible to fluctuations in moisture. In other words, the plants dry out too much, and their fruit is affected.
If the damaged portion of the fruit is small, you can trim it off and enjoy the rest of the fruit. Hopefully, the problem will fade with the prevention tips below!
Signs of Blossom-End Rot
Usually, blossom-end rot appears while the fruit is still green or ripening, so it often affects the first fruits formed on the plants.
Blossom-end rot starts with a small, depressed, water-soaked area on the blossom end of the fruit (the bottom, opposite the stem). The spot starts off looking like a dark bruise. As the spot enlarges, it becomes sunken and turns black or dark leathery brown in color. Half the fruit may eventually be affected.
Catherine Boeckmann
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It's was 25-30yrs ago, but when my son and I were growing tomatoes(Better Girls) from seeds in an egg crate, then later planting them in a raised bed, some of the tomatoes developed blossom end rot. Per the advice of my sister-in-law(horticulturist) we sprinkled bone meal around the bases of the plants. Worked great! Not sure of other conditions, but that's all I remember doing. I don't remember watering, just depended on rain. We had probably 20 plants or so. Bottom rot stopped & we had tons of sweet sun ripened tomatoes. I remember another sister-in-law coming and picking some of the tomatoes for herself, we had so many. Made great BLT sandwiches. Looking forward to trying to do that again, now, at retirement age. 👍👍👍🙂😋
As mentioned above, blossom-end rot is a condition caused by a lack of calcium. Unfortunately, the rot will not go away once a fruit is already affected, but following the advice below can stop the rot from progressing further and from affecting other developing fruit.
Thanks for the Tomato growing info~
First, choose vegetable cultivars that are tolerant of calcium deficiencies and less likely to show blossom-end rot symptoms.
Inconsistent watering is the main cause of calcium deficiency. Avoid watering your plants too much or too little. Instead, water consistently and evenly. If you forget to water, do not overwater. If it’s rainy, ensure plants have good drainage and the soil dries out (but do not cease to water completely). Overall, plants need about 1 inch of water (about 0.6 gallons) per square foot per week.
Use mulches to retain soil moisture during dry periods.
At the first sign of blossom end rot, I crush one calcium based antacid tablet (such as Tums, or I use the cheaper generic brand that comes in large bottles) in just enough water to dissolve it and pour at the base of the tomato/pepper/eggplant vine. The rest of the fruit then is fine. I've used this method for years.
How often do you do this treatment. Weekly, monthly? How often do you water your plants during July and August?
Just one application?
Thanks.
I was told to use Epsom Salt to help with blossom rot on my tomatoes
I use ground egg shells. I just haven’t figured out how much to use. I have two 64 ounce jars and a 32 ounce jar ground fine.
That’s magnesium so act makes it worse
For both the chickens and the planters, I crush shells a bit and then roast them slowly in the oven until browned. Crush a bit more and sprinkle in coop or potting soil I mix from a local plant nursery and a water treatment plant residue called 'sludge'...shells will keep slugs down in the planters and provides calcium to the chickens among it's other benefits.
Calcium Nitrate 15.5-0-0 a tspn/gal per week after fruiting starts is worth a try.
