QUESTION: What causes small tomatoes?
ANSWER: The most common cause for small tomatoes is stressed plants, but there are a few less common possible culprits as well. Plants can be stressed due to extreme weather conditions (such as heat or drought) and disease or infestation by insects. A lack of sufficient water can also result in small fruit on a tomato plant.
At the beginning of the season, plants usually need to be watered at least once per day, and as the days get hotter and plants get bigger, they may need two watering sessions daily. It’s simple to check whether tomato plants need water. Just stick a finger an inch into the soil to check whether the soil is moist or dry at this level. If it’s dry, the plants need water.
In extremely hot areas, you may need to protect your plants from the afternoon heat to avoid small tomatoes. Be careful how much shade you give plants, however, as too much can also limit the size of fruits. (That’s why you should be careful never to prune away leaves that shade a fruit cluster.)
Finally, if plants have been given an excess of fertilizer or nitrogen, they may respond by limiting the size of their fruit or not producing fruit at all. Lack of pollination can also cause small fruit or no fruit, which can be remedied by gently shaking the plant and other methods of self pollination.