Grit Blogs > A Long Time Coming

Why Are My Potatoes Setting Fruit?

A photo of Shannon SaiaI have a few years of growing potatoes under my belt now. I am no expert, by any means, but I’m not exactly a novice either. I pretty much know how potatoes work. I order the seed potatoes, plant them, and wait a few weeks for the dark green foliage to begin to emerge from the earth. When the plants are about six inches high, I start to hill them, and a few weeks later I do it again. After a few months the large plants begin to flower, at which point I can begin snooping around in the dirt for a “new potato” or two, being careful not to take more than one from each plant, and leaving the rest to continue to grow, invisible to me, in the earth. At no time do the flowering potato plants set fruit, like, say, the tomato. So imagine my surprise when I set out for my morning pass through my potato plants yesterday and found this.

King Harry Potato fruits 

I mean, what the heck?

I knew immediately that these must be my King Harry potatoes, a new hybrid from Cornell University, that were developed as follows:

"For the past several decades the Cornell potato breeding program, in conjunction with Dr. Ward Tingey of Cornell`s Department of Entomology, have been working to develop new potato varieties with sticky leaf hairs that trap and impede small insect pests. To introduce these leaf hairs, cultivated potato was first crossed with a wild potato species, Solanum berthaultii, and the hybrid was then crossed back to potato many times to eliminate unfavorable characters. After each generation, individuals with resistance to insects were identified, and used for crossing in subsequent

My assumption after reading this was that Solanum berthaultii must set fruit, and a quick web search revealed that this is, in fact the case. According to Eu Sol, a multi million Euro research project funded by the European Commission that focuses on improving the quality of potatoes and tomatoes, Solanum berthaultii is a South American potato with sticky leaves that trap insects. It’s “fruit is green, often with scattered white dots”.

So, mystery solved.

And let me take this opportunity to say that so far, everything I've read about the King Harry potato is true. I planted four varieties of potato, including some King Harry, over two months ago. I am also growing horseradish at the corners of my potato patch, and between those two things, I have found exactly one - ONE - mature potato beetle on one of my potato plants, and zero larvae. This is the most beautiful, dark green and verdant bunch of potato plants I have ever grown in my life. I'm expecting a big potato haul this year. Whoopee!