What causes tomatoes to crack?
All my tomatoes are cracking up
Is it safe to eat cracked tomatoes?
Splits or cracks are an aesthetic problem. The tomato will be just as tasty. Cut out the split area and eat as usual.
Splitting or cracking happens as a tomato is growing, the earlier it happens, the larger the crack. Some tomatoes are said to be crack resistant, but no tomato is crack proof. All tomatoes can occasionally crack.
There are two types of tomato cracks
- Concentric cracking – The tomato skin splits in circles or semi-circles spanning a portion or the entire circumference of the fruit. (Like the tomatoes at the top of this article.)
- Radial cracking – Splits run in straight lines going out from the stem.
There are three main reasons why tomatoes will crack
Too much fertilizer, inconsistent watering, temperature fluctuations lead to cracking. Just because this current crop is cracked, doesn't mean all future tomatoes will be cracked.
1. Improper fertilization: Over feeding plants will make tomatoes more prone to cracking. Take care not to over fertilize. This fall or winter, get a soil test and amend the soil as suggested.
2. Irregularly watering: The most common cause of cracks in tomatoes is heavy rainfall or over watering after a period of drought. A tomato fruit is 95 percent water, so tomatoes need lots of water to grow and develop fruit. Tomato plants should receive 1 to 2 inches of water a week. If this amount is not received as rainfall, then supplemental irrigation is necessary. Do not over water. Buy a rain gauge and use your local rain measurments as a watering guide.
Letting tomato plants dry out and then giving them large amounts of water to make up for it, can cause cracking. Inconsistent watering causes cracking because the sudden influx of rain or water causes the inside of the tomato expand, rupturing the outer skin.
3. Temperature extremes: Big changes in temperatures can cause cracking or splitting, especially with severe pruning. When too many leaves are removed from the plants, fruit is deprived of sun protection. Heating during the day and cooling at night can cause the skin to expand and contract, causing splits.
Extreme temperatures and heat waves are beyond our control. Leave enough foliage to protect tomatoes. If you are uncertain about pruning techniques, check with the local University Extension.
Heirlooms tend to have thinner skin and are more fragile. Some hybrids are bred to be more crack resistant. Look for Big Beef, an All America Selections Winner and very crack resistant.
Crack resistant tomatoes: Jet Star, Mountain Gold, Juliet, Beef Master, Big Boy, Rutger's Select, Whopper, and Mule Team.