Blossom End Rot

What Does Blossom End Rot Mean?

Blossom end rot is a disorder related to plant nutrition that creates a dark, sunken area on the blossom end (bottom) of a fruit. It is a common issue with many fruiting plants, including tomatoes, eggplant, peppers and more.

Blossom end rot is often related to a crop's lack of calcium and can be prevented, but not corrected.

Maximum Yield Explains Blossom End Rot

Plants require the right amount of nutrition and water, along with sunlight, in order to experience healthy growth. Sometimes, nutritional problems are not detected until the plant fruits, and a sunken, leathery, dark circle of rotting flesh appears on the bottom of the fruit. This is called blossom end rot, and is related to a lack of calcium in the soil, or the plant’s inability to absorb calcium present in the soil because of poor pH balance.

The best defense against blossom end rot is to test soil prior to planting. If calcium levels in the soil are low, amend it immediately and then retest. If calcium levels are good, but the pH balance is off (either too high or too low), amend using lime to balance it. Note that “fast-acting” lime is preferable for soil amendment, although if amending early in the season, ground limestone is acceptable, but will take time. Crushed eggshells added to garden compost will also help to improve soil calcium levels (again, over time).

Most plants prone to blossom end rot do better with a pH of 6.5 to 6.8 in contrast to the more common 6.2 to 6.8 for other vegetables. It’s important to note that adding too much nitrogen to the soil in the form of fertilizer can also bind calcium, preventing its uptake by growing and fruiting plants and leading to blossom end rot.

Blossom end rot can also be related to dry conditions after a wet start to the growing season. Thorough watering during dry spells can help prevent this problem.