What is this? There are fruits growing on my potato plants!
Yesterday while propping up some fallen potato stalks, I noticed something peculiar -- two green cherry-tomato-like fruits dangling from one of my bushes. Actually - just weeks earlier - I had read that some potato bushes actually produce these berries, so I kinda knew immediately what these were.
So what are these?
Anyone who grows potatoes knows that some potato plants produce flowers and some don't. Even more rare (but not unusual) is a potato flower that produces a tiny fruit. Each little fruit (poisonous - do not eat!) are the bearer of several dozen or so tomato-like seeds. They are actually called 'True Potato Seeds' or TPS. These are not the same as "Seed Potatoes," the store-bought (or home prepared) spuds with vines already growing from them - which most people use to grow their own potatoes.
Here's the strange part
As better explained in these Daughter Of The Soil blog posts (here and here), these seeds are not related to the tuber the flowers grew from. These seeds actually produce a variety of potato all its own:
"... TPS is not the tuber, but the actual seeds - which come from the plant's flowers and fruits. As seeds are produced by sexual means, a coming together of egg and pollen from different flowers or different plants, they represent a genetic recombination. In other words, they are not genetically identical to the parent plant. They are newly created individuals ..."
If I grow from seed, what should I expect?
As for the process, potatoes from TPS are sowed much the same as you would tomatoes or other plants - start growing indoors and transplant them outdoors some time in Spring. To extract the seeds, you would need to mash these little fruits up real good, place them in a glass of water for a few days. Wait until the seeds separate and sink to the bottom, dry out and save for next year.
The resulting harvest yield will be minimal, at least during the first year. Your first TPS harvest is likely to yield fewer & smaller potato spuds as opposed to growing by traditional means. However, if you save your best potatoes from your first harvest & plant those the following year, your potato harvest should improve. Repeat for several years and who knows, perhaps you have created your very own prized new potato variety.
My Potatoes, 6/15/11
So, what's the verdict on TPS
Growing from TPS is not for everyone. However if you have extra garden space, are willing to put forth more effort, you love experimentation, and are willing to spend years crafting your newly created potato variety, this may be a fun endeavor. Personally I have not decided whether to pursue this path -- for now I will extract the seed, preserve them, and decide my course of action later.