I love promiscuous pollination in every crop that I grow. I believe that if genetically diverse crops are able to rearrange their genetics, that they can solve problems for themselves that we are currently trying to solve with poisons, labor, or materials.

My definition of heirloom tomatoes is that the genetics worked a long time ago, in a faraway ecosystem, and then they got inbred and fixed into that place/time. As they move to new locations, and as ecosystems change over the years, they may not have the genetic toolkit to change with the new growing conditions. Selecting for tomatoes with more promiscuous flowers, and replanting seeds from naturally occurring hybrids can move a population of tomatoes towards local adaptation and can allow them to change with the ecosystem.

My experience, and that of my tomato breeding peers, indicates that the natural cross-pollination rate of tomatoes is around 3% to 5%. That can be increased to about 10% or more by selecting for flower types that are more suitable for cross-pollination:

1. Larger petals
2. Brighter petal colors
3. More and dustier pollen
4. Anthers that are not connected to each other (beefsteak type flowers)
5. Anther cones that are loose around the style
6. Stigmas that are outside the anther cone
   

I have included sketches of things that I look for when selecting for more promiscuous tomatoes.

The grand secret of plant breeding is that children tend to resemble their parents and grandparents, so if we start with great parents, we will tend to get great offspring. I love it when naturally occurring hybrids show up in my garden. They are new and exciting to me. They may not look, grow, or taste exactly like their mother, but that’s why I want them in my garden, because they might be tastier, or more adapted to current (and future) growing conditions in my ecosystem.

Have you found naturally occurring hybrid tomatoes in your garden? How did you like them? Are you still growing their descendants? Tell us about it in the comments.

Joseph Lofthouse
World Tomato Society Ambassador
The Beautifully Promiscuous and Tasty Tomato Project