The enigma behind the colossal growth of giant pumpkins explained.

Giant pumpkins, known for their colossal size, have long been a source of fascination. A team of researchers from Harvard University's Department of Organismic and Evolutionary Biology sought to understand the unique anatomy and physiology that allows these gourds to grow so large, particularly in 2014.

The growth of giant pumpkins is a harmonious blend of nature (genetics) and nurture (growing conditions). The seeds from which they sprout are genetically predisposed to grow into gigantic gourds due to selective breeding. Giant pumpkins grow big through a process of careful pollination, where pollen from male flowers of giant pumpkin plants (Cucurbita maxima) is used to fertilize female flowers, resulting in the fruit we know as the pumpkin.

However, the right growing conditions are equally crucial. Giant pumpkins require specific soils, water (up to 1,890 liters a week during summer), sunlight, and enough space to thrive. But the vascular system also plays a significant role in their size.

The vascular system of plants, consisting of xylem and phloem, is responsible for transporting substances throughout the plant. In the case of giant pumpkins, the phloem allows them to take up more sugar, providing the necessary energy for their enormous growth. The vascular system of giant pumpkins has a higher amount of phloem compared to other large squashes, a factor that contributes to their size.

The Harvard University team compared the leaves, stems, and fruit of three different varieties of giant pumpkin for their study. Some of the giant pumpkins sampled for the study were grown by dedicated growers, while others were grown by the research team themselves. The team found that the vascular system of giant pumpkins is a key factor in maximizing their size.

While genes play a role in the growth of giant pumpkins, the specifics of how that translates to the pumpkin's growth are still being researched. For instance, no publicly available information identifies specific researchers from the Department of Organismic and Evolutionary Biology at Harvard University in 2014 who discovered that the phloem tissue in the gnetophyte tree plays a key role in maximizing its size.

The findings from this study offer valuable insights into the growth of giant pumpkins and could potentially lead to further advancements in horticulture and plant biology. The winner of the 2020 Safeway World Championship Pumpkin Weigh-Off weighed approximately the same as two grizzly bears, a testament to the incredible size these pumpkins can achieve with the right combination of genetics, growing conditions, and a little bit of magic.