Why Are My Brandywine Tomatoes Splitting?

Splitting or Cracking Fruits

• Splitting or cracking of tomato fruits occurs when the outer skin of the tomato is unable to stretch to accommodate the growing fruit inside. Some varieties are more susceptible to this than others. Splitting can occur at any of the later stages of the fruit's development, from mature green fruits to completely ripe ones. If it happens when the fruits are green, the cracks grow deeper and longer as the fruit matures. Fully ripe fruit left too long on the vine may also split.

Watering

• One of the major causes of splitting in tomatoes is an inconsistent watering regime. During periods of dry conditions, growth slows and the outer skin of the fruit hardens. If the plant then receives a lot of water, growth starts up again rapidly, and the outer skin of the fruit cannot accommodate its internal swelling. The skin splits as a result. To prevent this, do not give large amounts of water periodically. Water regularly -- as often as every day in very hot weather, so that the soil is constantly damp, though not sodden.

Feeding

• Plants that receive an excess of nitrogen fertilizer are more susceptible to cracking. These plants grow lush and succulent, but produce fewer fruits. Tomato plants need potassium to develop fruits properly. Tomato fertilizer contains the correct balance of chemicals. Excessive watering washes nutrients out of the soil, resulting in the plant taking up more water. To help prevent splitting, feed plants regularly with a specialized tomato plant fertilizer -- according to the manufacturer's guidelines -- and do not overwater.

Temperature

• Fluctuations in temperature can cause uneven growth in tomatoes and fruit splitting. Sometimes gardeners remove the lower leaves of tomatoes to encourage ripening. This practice immediately exposes the fruits to the sun and higher temperatures. Inadequately or intermittently ventilated greenhouses can result in uneven temperatures for tomatoes too. Where possible, try to maintain a consistent temperature for their tomatoes. Ensure greenhouses are adequately ventilated and consider the weather conditions before removing the lower leaves of tomato plants.