Blossom End Rot (BER) is a common physiological disorder in tomatoes, appearing as a dark, sunken, leathery spot on the bottom of the fruit. While frustrating for gardeners, the affected fruit is generally safe to consume, provided the damaged tissue is completely removed. Understanding the cause of BER and how to handle affected fruit helps minimize waste and ensures a safe harvest.
Can You Eat Blossom End Rot Tomatoes
BER is caused by a localized calcium deficiency within the developing fruit tissue. This physiological problem causes cell wall membranes to collapse, resulting in the characteristic dry, sunken lesion. Since BER is not caused by a fungus, bacteria, or other infectious agent, the affected tissue itself is not toxic to humans.
The disorder is strictly limited to the lesion site and does not spread throughout the tomato’s healthy flesh. The unaffected portion of the tomato remains safe and nutritionally intact for consumption. This differs significantly from true fungal or bacterial rots, which often produce toxins or spread throughout the fruit, making them unsafe to eat.
If the BER lesion is small and dry, the tomato is suitable for eating after the damaged section is excised. However, the rot site can become an entry point for secondary organisms like mold or bacteria. If secondary spoilage is extensive, leading to a wet, mushy, or foul-smelling spot, it is better to discard the entire tomato.
How to Salvage and Use Affected Fruit
Salvaging tomatoes with Blossom End Rot is a straightforward process that minimizes food waste. Begin by carefully inspecting the affected fruit to determine the extent of the damage. If the lesion is dry, leathery, and confined to a small area, the tomato is a good candidate for salvage.
To prepare the fruit, use a sharp knife to cut away the entire affected area, removing all dark, sunken tissue. Cut slightly into the healthy flesh to ensure no compromised tissue remains.
Salvaged tomatoes often have a slightly compromised texture, making them less desirable for fresh eating. The best uses involve cooking, as heat and processing mask minor textural imperfections. They are ideal for making sauces, purees, soups, canning, or blending into juice. If the rot appears internally as gray or black sections, trim those away before processing.
Addressing the Root Cause
Preventing Blossom End Rot focuses on ensuring the plant can effectively absorb and transport calcium to the developing fruit. The issue is rarely a lack of calcium in the soil, but rather the plant’s impaired ability to move it during rapid growth. Calcium movement is primarily tied to the transpiration stream, meaning it moves with water evaporating from the leaves.
The most significant factor in prevention is maintaining consistent soil moisture, as dramatic fluctuations restrict calcium uptake. Tomatoes require about 1.5 inches of water per week during fruiting. Using mulch helps conserve moisture and prevents the soil from rapidly drying out between watering sessions. Avoid letting the soil become bone-dry and then soaking it excessively, as this inconsistent pattern is a major trigger for BER.
Managing soil pH is another component of prevention, as calcium absorption is maximized when the soil pH is within the range of 6.0 to 6.5. A soil test is necessary to accurately determine the pH and existing calcium levels before applying amendments. If a true calcium deficiency is confirmed, adding dolomitic or high-calcium limestone a few months before planting can help correct the soil chemistry.
While water and pH management are the long-term solutions, strategic use of calcium amendments can offer a temporary boost. Applying a calcium-rich product like gypsum to the soil can provide available calcium, but it must be watered in deeply. Foliar calcium sprays are generally ineffective for correcting BER because calcium is poorly transported from the leaves to the fruit.