Hand-Pollinating Indoor Tomatoes

An indoor tomato can flower beautifully and still produce no fruit. The flowers open, fade and fall off. Usually nothing is wrong with the plant: the flowers simply weren't pollinated, because indoors there is no wind and no bees.

Why Tomato Flowers Need Help Indoors

Each tomato flower has both male and female parts, so a single flower can pollinate itself. But the pollen is held inside the flower and only falls out when the flower is shaken. Outdoors, wind and bumblebees do the shaking; a bumblebee's buzzing vibrates the pollen loose. Indoors, you have to do it.

How to Hand-Pollinate

1. Wait for open flowers. Tomato flowers are ready when the yellow petals open and fold back.
2. Pick the time of day. Late morning to early afternoon, when the air is warm and dry, is when pollen releases best.
3. Vibrate each flower cluster for a few seconds: hold an electric toothbrush against the stem just behind the flowers, flick the stem lightly with a finger, or move a small soft paintbrush gently inside each flower.
4. Repeat every day or two while flowers are open. Each flower is only receptive for a few days.
5. Watch for fruit. A pollinated flower's base starts to swell into a tiny green tomato within about a week.

When Pollination Isn't the Problem

If you pollinate and the flowers still drop, look at the conditions. Very hot or cold temperatures, too little light and too much nitrogen all stop fruit from setting. See tomato flowers falling off for the full checklist, and grow lights for indoor tomatoes for light and temperature.

Back to the Kratky method for tomatoes.

Frequently Asked Questions