Did you know potato plants can produce fruit? My Adirondack Blues are covered with small green fruit that look like unripe grape tomatoes. What is going on here? Is the fruit edible and are my potato tubers OK?
Luckily, the fruiting of the plant has no bearing on the crop of tubers growing under the ground. Some varieties of potato are more prone to fruit than others but it doesn't happen every year even for those plants. Environmental factors seem to play a role. I am used to seeing the potato flowers fall off the plant pretty quickly and that is prompted by hot weather. If the weather is cooler, the flowers live longer, leaving them available for pollination and fruit production.
The fruit, although cute, is not edible. In fact it is poisonous and can cause headaches, abdominal pain, and diarrhea. Luckily, it is very bitter so one bite should warn people away. If you have children or pets, however, I would make sure they cannot access the plants. Potatoes are part of the Deadly Nightshade family along with tomatoes, peppers and eggplant and it is the chemical solanine that makes parts of these plants toxic, including the fruit of the potato. Solanine is also the reason potatoes turn green if left in the light.
Tomatoes and potatoes are the closest relatives in the Nightshade family and can share disease and pests, so it makes sense that the potato and tomato fruit would be similar. Potato fruit contains hundreds of seeds, just like a tomato, and are harvested using the same method by squeezing the pulp into water and letting the seeds rise.
You may be asking at this point, why don't we plant potato seeds rather than seed potato tubers? The answer is that potato seeds do not produce offspring true to the parent plant. This means that my Adirondack Blue seeds will not produce replicas of the plant but a variation. Breeders do use seeds to create new varieties of potatoes but it takes several generations to achieve stability.
Seed potatoes produce a consistent potato crop because they create clones of the parent plant. Actually, 'seed' potato is not accurate because the tuber is not a seed. Potato tubers are enlarged underground stems that store nutrients (starch) for the plant. Potato 'eyes' are actually nodes or buds, just like on an above ground stem. When we cut up a potato, making sure to have eyes on each piece, then plant them in the soil, we are actually propagating the mother plant, just like we propagate other plants by taking cuttings and planting them.
See you in the garden,
Here are a couple of sites I used in my research for this post: