My tomatoes flowered but didn’t set fruit. What’s up?
Sometimes, despite all the love you give them, tomatoes fail to set fruit. Assuming you did not give the plant too much Nitrogen, it may be weather-related: Nighttime temperatures that remain above 70 or temperatures below 50ish interfere with pollination. Fruit set can also be hampered by over-feeding with Nitrogen or by irregular watering.
Hot, dry conditions at blossom time prevents proper pollination and can causes buds or tiny fruit to drop. If it’s early enough, hopefully a next round of flowers appears during more favorable weather. I know some gardeners who hose down their plants if the weather is inhospitable, hoping to encourage fruit set.