Blossom End Rot: Causes, Treatment, and Prevention

Blossom End Rot is a common problem gardeners face, especially in tomatoes, peppers, and squash. It appears as a brownish-black spot on the blossom end of the fruit and can be frustrating, as it damages the fruit and can spread to other plants. In this article, we’ll take an in-depth look at the causes, treatment options, and prevention strategies, as well as discuss how to identify it and answer some frequently asked questions about it. By the end of this article, you’ll have a better understanding of this common gardening problem and how to manage it effectively. Let’s dig in!

What is Blossom End Rot?

Blossom end rot is essentially caused by a lack of calcium in the developing fruit. Calcium is essential for good cell structure and development, and when there isn’t enough of it available, the cell walls break down and the fruit becomes soft and mushy on the blossom end. It looks like rotting tissue.
Once it develops, there’s no way to restore the fruit, and it has to be removed from the plant. If the condition isn’t dealt with at the root cause, it can lead to more problems such as fungal infections.

Causes of Blossom End Rot

1. Calcium Imbalance
   • While calcium deficiency in the soil is not always the direct cause of blossom end rot, it is a main contributor to the problem. You can learn how to add calcium to the soil easily.
     Primarily, calcium imbalance occurs with fluctuations in soil moisture levels. Fluctuations in moisture affect the plant’s ability to absorb calcium efficiently, leading to an imbalance in calcium distribution.
2. Inconsistent Watering
   • Irregular watering, such as alternating between overwatering and underwatering, can disrupt the uptake and distribution of calcium within the plant. This inconsistency affects the overall health of the fruit and increases the likelihood of blossom end rot.
3. Temperature Fluctuations
   • Temperature fluctuations can also lead to Blossom End Rot. When the temperature fluctuates wildly, it can cause the plant to lose the ability to process calcium effectively. While there’s not much you can do about this problem, if you live in an area where this is a problem, consider using raised beds or a greenhouse.
   • If you live in an area of extreme heat, try using shade cloth to cover susceptible plants during the hottest hours of the day.

Treatment of Blossom End Rot

1. Adjust Soil pH
   • Learn how to test the soil’s pH level using a testing kit and ensure it falls within the appropriate range for the plant with the problem. If the pH is too high or too low, consider adjusting it by adding appropriate soil amendments like lime or sulfur.
2. Consistent Watering
   • Maintain consistent moisture levels in the soil, ensuring it remains evenly moist but not waterlogged. Check the soil regularly and use watering practices that work for your area and soil, especially during drought or excessive heat.
3. Calcium Supplementation
   • While calcium deficiency is not the primary cause, adding calcium amendments to the soil can help address any imbalances. These supplements can be added to the soil during planting or around the root base once the problem occurs.

Prevention of Blossom End Rot

1. Soil Preparation
   • Before planting, ensure the soil is well-draining and rich in organic matter. Making and using compost can improve the soil’s structure and nutrient availability, promoting healthy fruit development. Making your own compost is easy. Some people also use vermicomposting as an additional way to improve the health of their soil.
2. Consistent Watering
   • Using a soaker hose or drip irrigation system is an easy way to provide a consistent and regular supply of water.
3. Use Mulch
   • Apply a layer of organic mulch around the base of plants to help regulate soil moisture levels, reduce water evaporation, and maintain a more consistent growing environment. We use the deep mulch method of gardening except in the corn and pea field.
4. Regular Inspections
   • You have to visit the garden at least once a day to catch problems early. Early detection of blossom end rot can help prevent its spread to other fruits. To prevent the spread, remove and discard affected fruits to prevent further development of the disorder. We don’t add diseased fruits to the compost, we give them to the chickens when appropriate or to the pigs.
5. Balanced Fertilization
   • If your soil isn’t alive and healthy, you can take steps to amend and heal it. You can also use a Super Soil recipe. We seldom use fertilizer because of the steps we have taken over the years to build healthy, living soil. When we do, we make the fertilizer ourselves. If you want to use fertilizers, we recommend using an organic one.

Old Timers Tip

15 years ago, a 94-year-old gardener, Mr. Ted, told us to remove the blooms once the fruit formed to help prevent blossom end rot. We tried it and to our surprise, it seemed to help. Now it could have been the soil was getting healthier or some other unknown factor but since it made a difference, we remove the blossoms once the fruit is fully formed.

Frequently Asked Questions about Blossom End Rot

• Can Blossom End Rot be Cured?

While it’s not possible to “cure” Blossom End Rot after it has already developed, it can be effectively managed and prevented through proper care and attention to the soil, water, temperature, and pH of your plants.

• Is Blossom End Rot Harmful to Humans?

No, Blossom End Rot does not affect the safety or edibility of the fruit, so it’s not harmful to humans. You can remove any affected portions of the fruit and consume the rest as normal if you choose to. I have to say I’ve never eaten anything that had blossom end rot. When we have a problem we catch it early so the fruit hasn’t fully developed so we give them to the chickens or pigs.

• How Do I Know if I Have Blossom End Rot in My Garden?

Blossom End Rot can be identified by the appearance of a brownish-black spot on the blossom end of the fruit that looks like it’s rotten. If you notice this on the fruit, this is likely the problem.

If in doubt, ask a local gardener, or someone at the Farmer’s Market or you can take a sample to a local nursery.

Wrap Up

Blossom end rot can be frustrating for gardeners. By addressing potential causes such as calcium imbalances, inconsistent watering, and nutrient deficiencies, as well as implementing preventative measures, gardeners can reduce the occurrence of blossom end rot and enjoy a bountiful harvest.

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