Tomato blossom-end rot is a condition which occurs on tomato plants as well as pepper plants, squash plants and watermelon plants. Tomato blossom-end rot is a result of a calcium deficiency in developing tomato plant fruits which can result in slowed growth of the tomato plant or damaged root systems.
Many factors can contribute to tomato blossom-end rot in the vegetable garden.
Tomato blossom-end rot appears as round spots on the blossom end, opposite the stem end of the tomato fruits. These sunken spots may appear as if they are water soaked, and will start out as brown spots, rapidly progressing to black as the area of tomato blossom-end rot increases. Many factors contribute to the manifestation of tomato blossom-end rot, but at their core is the same causative factor, a lack of calcium in the developing tomato fruits. Rapid early season planting which is followed by a spell of hot, dry weather can be a major causative factor as can extreme fluctuations in the moisture of the soil in which the tomato plant survives. Soil can be problematic in another way as well, in the case of excess salt in the soil s composition.