Why Can't the Starks Build Greenhouses in the North?

The harsh northern climate of the A Song of Ice and Fire series, particularly the Game of Thrones universe, presents significant challenges to agriculture, especially in the vast expanse known as the North. Jon Snow, in his ambitious plans for the Wall, considered the idea of establishing greenhouses to ensure a year-round food supply. However, the practical realities of medieval technology and geography make such a venture both financially and logistically challenging.

Cost and Resource Constraints

During the medieval period, the construction of greenhouses would have been an extremely expensive endeavor. Glass, the primary material for the structural and leakage-proof components of a greenhouse, was one of the most valuable and fragile commodities available. These difficulties in securing and transporting glass would have been exacerbated by the challenging and often broken transportation routes of the era.

The North, being the largest of the Seven Kingdoms, requires a substantial amount of glass to create a network of greenhouses large enough to produce enough food year-round to alleviate the region’s food shortage. Even if the North had the financial means to fund such a project, the cost of importing enough glass to support many greenhouses could easily bankrupt the Iron Bank of Braavos, the Iron Throne’s treasury, or House Stark’s resources.

Soil Quality and Climatic Challenges

Another significant factor that may hinder the success of numerous greenhouses in the North is the quality of soil. The North’s soil, while not as poor as it is often portrayed in the series, is still less fertile than the fertile soils of the Riverlands, the Westerlands, and the Reach. Even with advanced greenhouses, the natural productivity of the soil would not improve magically. The introduction of glass greenhouses would not solve the fundamental issues of soil quality and climate in the region.

Therefore, importing food from other regions or enhancing the current agricultural practices on the North’s own land would be the most practical options for addressing the food shortage in the region. Transporting food is often a cheaper solution than establishing an infrastructure that requires substantial investment in resources and technology.

Jon Snow's Vision and Practical Considerations

Expensive and Risky Investment

When Jon Snow contingency plans at the Wall, he considers the idea of building greenhouses supported by a large loan from the Iron Bank of Braavos. However, this plan, even if it could be executed, would also require the expertise of Myrish glassworkers to train Northmen in glassmaking. Shipping fragile glass over long distances and across harsh terrain would be a high-risk operation, leading to potential breakage and difficulty in replacing damaged panes.

Additionally, the cost of hiring skilled glassblowers and glaziers from distant Myr and bringing them to the North would be astronomical. While the concept of castle gardens in Winterfell hints at a post-apocalyptic world, the realism of medieval times would require more tangible solutions to the region's food shortages.

Climatic and Technological Limitations

Even if Jon’s vision were feasible, the problem of generating sufficient heat for the greenhouses would remain. Historical evidence indicates that the concept of artificially heated greenhouses emerged much later in medieval Europe, around the 1450s in Korea and the 17th century in the Netherlands and England. The requirement for a heating system, such as the ondol system in Korea or the use of stoves in England, underscores the technological limitations of the time.

In Winterfell, the use of natural hot springs for heating the glass gardens and Wintertown is a more pragmatic approach. The water from these springs is piped through walls and chambers to maintain comfortable temperatures throughout the year. This natural heating system makes Winterfell significantly more habitable during the harsh northern winters, while also supporting the cultivation of fruits, vegetables, and flowers in the glass gardens.

While Jon’s idea of establishing extensive glass gardens is revolutionary, the practical realities of medieval technology and the unique challenges of the North make it a challenging and perhaps unnecessary endeavor for the region.