Why Is My Tomato Flowering But Not Making Fruit?

This is a subtly different problem from flowers dropping off, and it is worth its own look. Here the flowers may stay on the plant, open fully, and look perfectly healthy — but they wither and fade without ever swelling into a tomato behind them. The plant is flowering but not setting. When this happens, the issue is pollination: the flower opened, but the pollen never did its job. Let me explain why that happens and how to fix it.

How a tomato actually sets fruit

Understanding this makes everything else click into place. A tomato flower is self-fertile, meaning it contains both the pollen and the part that needs to receive it, all in one bloom. It does not need a second plant. But the pollen still has to fall from the upper part of the flower onto the receptive stigma, and that requires physical movement — a breeze, the buzz of a bee's wings, or vibration. If the pollen never moves, the flower cannot self-pollinate, and no fruit forms even though the flower was perfectly good.

Why pollination fails

Several things stop that pollen moving or working. Still air is a big one: plants grown in a sheltered corner, indoors, or in a greenhouse often lack the wind that would normally shake the flowers. A shortage of pollinating insects, whether from cold weather keeping bees away or a garden with few flowers to attract them, has the same effect. And heat strikes again — when it is very hot, above about 90 degrees Fahrenheit, the pollen itself becomes unviable or too sticky to transfer, so even a well-shaken flower fails to set. Very dry or very humid air interferes with pollen movement too.

Hand-pollinate to force the issue

The most satisfying fix is to do the pollination yourself, and it genuinely works. On a warm, dry day around midday, when pollen is most active, gently shake or flick each flower truss with your finger. For a stronger effect, hold a battery toothbrush or a small electric vibrator against the stem behind the flowers for a second or two — the vibration mimics a bee and shakes the pollen loose to fall onto the stigma. Do this every day or two while the plant is flowering. In greenhouses and sheltered spots, this single habit can transform a fruitless plant into a productive one.

Address the conditions too

Alongside hand-pollinating, improve the conditions. Open up greenhouses and tunnels on warm days to let in air and insects. Grow flowers nearby to attract bees to the garden. During heatwaves, provide light afternoon shade to keep the flowers within the temperature range where pollen stays viable, and keep watering steady so the plant is not stressed. Avoid heavy nitrogen feeding, which favours leaves over fruit; a potassium-rich feed supports fruiting instead.

Give it a little time

Finally, remember that a flower does not become a visible fruit overnight. After successful pollination it takes several days before you see the tiny green tomato beginning to swell behind the faded flower. So if your plant has only just started flowering, give it a week or so before concluding nothing is setting. Once the conditions and pollination are right, you will see those little fruits appear, and then it is simply a matter of growing them on.