Cause of Tomato Blossom Drop
Many of the problems that cause blossom drop can be difficult to control because they are related to temperature and plant stress, including:
Temperatures that are too high or too lowLack of pollinationToo much or too little nitrogenHumidity that’s too high or too lowLack of waterStress from insect damage or diseaseExcessively heavy fruit
The most common cause of tomato blossom drop is temperature. Tomato plants can get stressed if the high daytime temperature is above 85 degrees Fahrenheit, the high nighttime temperature is above 70 degrees, or if the low nighttime temperature is below 55 degrees. Tomatoes grow best if daytime temperatures range between 70 and 85 degrees Fahrenheit. While the plants can tolerate more extreme temperatures for short periods, several days or nights with temps outside the ideal range will cause the plant to abort fruit set and focus on survival. According to the University of Nevada Cooperative Extension, temperatures over 100 degrees sustained for four hours can cause tomato flowers to abort.
Controlling Tomato Blossom Drop
Nothing will guarantee fruit set. Because factors like temperature and humidity are out of the gardener’s control, sometimes you just have to be patient and wait for conditions to correct themselves. If the weather seems fine and other gardeners in your area are not having fruit set problems, consider the cultural causes of tomato blossom drop. Choosing a suitable variety and keeping your plants healthy will give you an edge:
