Tomatoes on a Vine are Rotting on the Bottom

Appearance

• Blossom end rot begins as a light brown or tan-colored lesion on the blossom end of the tomato -- the bottom end. Often, this lesion is very watery. Over time, the lesion darkens, becomes black, grows very leathery to the touch and eventually takes over the entire tomato. Blossom end rot occurs on tomatoes still on the vine and continues to affect the tomato until it has been harvested.

Cause

• Blossom end rot is often caused by poor soil nutrition or unbalanced soil nutrition. This nutrient imbalance is usually a result of insufficient calcium or excessive nitrogen or potassium. Blossom end rot also is almost always partly or even mostly a result of irregular watering practices. When tomatoes are subjected to wide fluctuations in the amount of water they receive, blossom end rot develops.

Prevention

• The easiest way to prevent blossom end rot is to avoid stressing the plants and to put into place a regular irrigation schedule. A steady supply of water is the best solution to preventing blossom end rot. The soil around the tomato plants should not be soaking wet on a regular basis. Properly moist soil is damp to the touch 1 inch below the ground surface. Using mulch helps keep the soil adequately moist without overwatering.

Use

• Tomatoes that have suffered from blossom end rot should be picked as soon as they are ripe or even when they are still green if you are able to make use of green tomatoes. Tomatoes that have suffered blossom end rot are still usable. Slice off the affected area and use the remainder of the tomato as soon as possible. One way of salvaging affected tomatoes is to use them for tomato sauce, where having parts of tomatoes does not pose too many difficulties.