Blossom End Rot in Squash: Causes, Prevention, and Treatment
What is Blossom End Rot?
Blossom end rot is a common problem that affects squash plants, causing the bottom of the fruit to rot and turn black. It’s caused by a calcium deficiency, which can occur when the plant doesn’t get enough calcium from the soil or when the soil pH is too low.
Symptoms of Blossom End Rot
The main symptom of blossom end rot is a black indentation on the bottom of the squash fruit. The rot can spread and cause the entire fruit to become soft and mushy. Affected fruit is not dangerous to eat, but it will not taste very good.
Causes of Blossom End Rot
- Calcium deficiency: The most common cause of blossom end rot is a lack of calcium in the soil. Calcium helps plants build strong cell walls. When there’s not enough calcium, the cells at the bottom of the fruit, which grow the fastest, collapse and rot.
- Low soil pH: Soil pH is a measure of how acidic or alkaline the soil is. Squash plants prefer a soil pH between 6.0 and 6.5. If the soil pH is too low (acidic), it can make it difficult for the plant to absorb calcium from the soil.
- Uneven watering: Squash plants need consistent watering. If the plant goes through drastic changes in the amount of water it gets, it may not be able to take up the calcium it needs at the crucial time when the fruit is being formed.
Preventing Blossom End Rot
- Add a low nitrogen fertilizer to the soil before planting: Nitrogen is an important nutrient for plants, but too much nitrogen can cause an imbalance of growth between the roots and the leaves. If the leaves grow too fast, the plant doesn’t have enough roots to take up the calcium the squash fruit will need.
- Water evenly: Water squash plants deeply and regularly, especially during hot, dry weather. Avoid overwatering, as this can also lead to problems.
- Ensure adequate calcium in the soil: You can add calcium to the soil by adding gypsum or lime. Gypsum is a natural mineral that contains calcium sulfate. Lime is a calcium carbonate compound that can help raise the soil pH.
Treating Blossom End Rot
- Add a calcium-rich foliar spray: A foliar spray is a solution that is applied to the leaves of the plant. You can make a calcium-rich foliar spray by mixing 1 tablespoon of calcium chloride or calcium nitrate in 1 gallon of water. Apply the spray to the leaves of the plant every 10-14 days.
- Add gypsum to the soil: Gypsum is a natural mineral that contains calcium sulfate. You can add gypsum to the soil around the squash plants at a rate of 1-2 pounds per 100 square feet.
- Raise the soil pH to 6.0-6.5: If the soil pH is too low, it can make it difficult for the plant to absorb calcium from the soil. You can raise the soil pH by adding lime. Lime is a calcium carbonate compound that can help neutralize acids in the soil.
Conclusion
Blossom end rot is a common problem, but it can be prevented and treated. By following the tips in this article, you can help your squash plants grow healthy and produce delicious fruit.