Sun-ripened tomatoes are the result of thousands of pollen grains moving at just the right time to pollinate flowers. All types of tomatoes—from beefsteaks that are larger than your hand to bite-size grape tomatoes—are usually pollinated by insects or the wind. But when pollen doesn’t naturally get where it needs to go, you’ll end up with flowers but no fruit. In this case, a little human intervention may be needed. This guide will show you how to pollinate tomatoes by hand to increase your harvest.

Are Tomatoes Self Pollinating?

Similar to related plants such as eggplants and peppers, each tomato flower has both male and female plant parts that allow it to self-pollinate. The pollen simply needs to move from the anther (male plant part) to the stigma (female plant part), all within the same flower. Insects, usually bees, or a strong breeze will transfer the lightweight pollen grains from anther to stigma.

Pollination can be compromised when tomatoes are growing in a location protected from the wind, such as an enclosed patio or near buildings that block air movement. Tomatoes growing indoors lack both wind and bees to help with pollination.

Other hurdles to pollination include very wet or humid conditions during flowering. Pollen clumps when wet and doesn’t move well, preventing pollination. Extreme dry conditions also present a problem because the usually sticky stigma becomes dry so pollen has trouble adhering to it.

When to Pollinate Tomatoes by Hand

The best time to hand pollinate tomatoes is shortly after the flowers open fully. Tomato flowers often remain open for a few days, providing an ample window for pollination. You can pollinate tomato flowers anytime from late morning through early evening. Avoid early morning when the flowers are wet with dew. The dew causes the pollen to clump together, making it difficult to transfer.

How to Pollinate Tomatoes

Hand pollinating tomatoes is a simple process because each tomato flower contains both male and female plant parts. With the right timing and techniques, you can help move pollen where it needs to go to produce fruit.

1. Select dry tomato flowers.

Hand pollinate tomato flowers when they are thoroughly dry. Avoid morning when flowers are damp with dew and late evening when dew descends on the garden. Wait at least two hours after a rain event before hand pollinating.

2. Move the pollen.

No special tools are needed to pollinate tomatoes—just tap on the base of the flower with your finger. The movement will dislodge the pollen and gravity will help at least some pollen grains fall on the stigma. Some people find a thin pencil helpful for tapping the base of flowers in tightly packed flower clusters. Electric toothbrushes are the tool of choice for others. Touch the tip of the vibrating toothbrush to the base of the flower for a few seconds.

3. Repeat daily for 3 days.

Hand pollination is most successful when the flowers are hand pollinated for 3 consecutive days. The repetition accounts for immature pollen grains and mediates weather challenges by offering multiple opportunities for the pollen to transfer to the stigma.