In cannabis cultivation, growers sometimes encounter an unwelcome development: “nanners.” This refers to male flower structures on a female plant. Their presence can compromise harvest quality and yield. Understanding nanners and their formation is important for plant management.
What Nanners Are
Nanners are exposed stamens, which are the male reproductive organs responsible for producing pollen. They emerge directly from within the calyxes or buds of a female cannabis plant. They typically appear yellow, elongated, and curved, resembling tiny bananas. Unlike traditional male pollen sacs, nanners are often hidden within the female bud, and their pollen is already exposed. Their presence indicates a form of hermaphroditism, where a plant exhibits both male and female sexual characteristics.
Why Nanners Appear
Nanners develop primarily due to either environmental stress or genetic predisposition. Environmental stressors can include inconsistent light cycles, such as light leaks during the dark period, or extreme temperatures, particularly sustained heat above 80°F (27°C) or significant temperature drops during the night. Nutrient imbalances, like deficiencies in potassium or magnesium, or fluctuations in pH levels, can also induce this stress response. Physical damage to the plant can also contribute to nanner formation.
Beyond environmental factors, some cannabis strains are more genetically inclined to develop hermaphroditic traits, especially those derived from unstable feminized seeds. Even in otherwise healthy plants, “late-stage nanners” can appear naturally as the plant nears the end of its life cycle, representing a final attempt to self-pollinate and produce seeds.
How to Identify Nanners
Identifying nanners requires regular inspection of cannabis plants, especially during the flowering stage. They are typically small, yellow, and elongated, often resembling miniature bananas, though they can sometimes appear lime green or white. They frequently emerge from within the developing buds or calyxes, sometimes in clusters.
Growers should pay close attention to dense buds and the upper parts of the plant, as these are common locations for nanner development. A magnifying glass can be a useful tool for early detection, as nanners can be quite minute. Prompt identification helps mitigate their potential impact on the harvest.
The Impact of Nanners
The primary negative consequence of nanners is self-pollination. Nanners release pollen that can fertilize the female plant’s own flowers and any other female plants in the vicinity, leading to the development of seeds within the buds.
The presence of seeds significantly reduces the quality, potency, and market value of the harvest, resulting in what is often referred to as “seedy weed.” The plant’s energy is diverted from cannabinoid and terpene production towards seed development, leading to a less desirable final product. Even if no pollination occurs, a plant affected by nanners may still produce less dense and airy flowers.
Managing Nanners
Upon discovering nanners, growers should take careful action. If only a few nanners are present and the plant appears healthy, they can often be meticulously removed. This process involves using sterilized tweezers to gently pluck the nanners, taking care to avoid disturbing them and releasing pollen.
It is advisable to turn off fans in the grow space during removal to prevent any accidentally released pollen from circulating. If the problem is widespread or appears early in the flowering stage, isolating the affected plant or, in severe cases, culling it entirely may be necessary to protect the rest of the crop from pollination. For nanners that appear very late in the flowering cycle, near harvest, early harvesting might be considered, as seeds may not have sufficient time to fully develop.
Preventing Nanners
Proactive measures minimize the risk of nanner formation. Maintaining a stable and consistent environment is important. This includes ensuring uninterrupted dark periods during the light cycle, free from light leaks, and regulating temperatures within optimal ranges, such as 70-80°F (21-27°C) during the day and 60-70°F (15-21°C) at night during flowering. Humidity levels should also be controlled, typically 40-60% in early flowering and 30-50% in late flowering.
Proper nutrient management, providing balanced nutrition, and maintaining stable pH levels prevent deficiencies or toxicities that can induce stress. Selecting stable, feminized seeds from reputable breeders can also greatly reduce the likelihood of nanners appearing. Consistent and thorough inspection of plants throughout their growth cycle, particularly during the flowering phase, allows for early detection and intervention.