The potato plant, Solanum tuberosum, is a member of the Solanaceae family, which also includes tomatoes and peppers. As the plant matures, it naturally enters a reproductive stage by producing flowers, which often prompts gardeners to ask whether this process affects their harvest. The common concern is that flowering diverts energy that could otherwise be used to enlarge the subterranean tubers. The decision of whether to allow the plant to flower or to remove the blossoms is a practical choice that depends largely on a gardener’s ultimate goals.
The Biological Role of Potato Flowers
The potato plant has two distinct methods of reproduction: sexual, through flowers and seeds, and vegetative, through underground tubers. The plant must allocate its energy reserves, primarily carbohydrates produced through photosynthesis, between these two competing systems. The flowers are the plant’s means of sexual reproduction, and if pollinated, they develop small fruits containing true potato seeds.
The belief that flowering significantly reduces tuber yield stems from the principle of resource allocation. Flowers and developing fruits act as “sinks” for the plant’s energy, drawing photosynthates away from other growth points, including the developing tubers. Research confirms that the development of inflorescences, especially fruit, can create competition for assimilates like sugars and amino acids, which are also needed for tuber growth.
The impact of this energy diversion is highly dependent on the specific potato variety and environmental factors. Some modern cultivars have been bred to prioritize tuber growth, meaning they may flower profusely without a measurable reduction in the final harvest. For many varieties, tuber initiation, the process of forming the potatoes, begins before the plant even flowers.
Practical Considerations for Removing Flowers
The practice of removing potato flowers, sometimes called “deadheading,” aims to eliminate the energy sink and redirect resources back to the tubers. While this concept is scientifically sound, the actual measurable increase in tuber yield for the average home gardener is often minimal. For most common garden varieties, the energy invested in flowers is relatively small compared to the plant’s total energy budget.
The labor involved in constantly monitoring and removing the flowers can outweigh the negligible yield gain. In some studies, the removal of flowers and buds has resulted in an increase in total tuber yield, with some research showing increases of around 2% to 17% depending on the specific cultivar and environmental conditions. This slight increase is more relevant for commercial growers where even a small percentage gain across acres translates to significant profit.
Manually pinching off flowers can create small wounds, potentially diverting energy toward healing damaged tissue rather than focusing on tuber bulking. For the home gardener, a more effective strategy for maximizing yield involves focusing on proven practices. These include consistent watering, proper hilling to protect the tubers, and balanced fertilization.
Understanding Potato Fruit and Toxicity
After a potato flower is successfully pollinated, it can develop into a small, round fruit that resembles a miniature green tomato or berry. These fruits are a natural consequence of sexual reproduction and contain the plant’s true seeds. While professional breeders use these seeds to develop new varieties, the fruit itself should never be consumed.
The potato fruit, along with the leaves and stems of the plant, contains high concentrations of glycoalkaloids, primarily solanine and chaconine. These compounds are a natural defense mechanism for the plant and are toxic to humans and pets. Ingestion of potato fruits can cause gastrointestinal distress, headaches, and in high doses, more serious symptoms.
The concentration of solanine in these berries is significantly higher than the safe levels found in properly stored potato tubers. Gardeners with children or pets should be vigilant in removing any forming green berries to eliminate the risk of accidental poisoning.