Vertical farming refers to the practice of growing crops in stacked layers, often integrated into urban buildings or other controlled environment agriculture (CEA) systems. It typically uses hydroponic, aquaponic, or aeroponic methods to grow crops without soil, ensuring efficient water use and space optimization. The goal of vertical farming is to maximize productivity per square meter by utilizing innovative technology like artificial lighting and climate control systems to create the ideal growing conditions year-round.

The concept of vertical farming was first popularized by Dr. Dickson Despommier, a professor at Columbia University, in the early 2000s. Despommier envisioned high-rise buildings that could house urban farms, allowing cities to produce food locally and reduce reliance on traditional agriculture, which consumes vast land and resources (1). It wasn't until recent advances in technology, such as LED lighting and automation, that the feasibility of large-scale vertical farming became a reality (2). Since then, vertical farming is evolving into a commercially viable industry, particularly as urban populations grow and demand for sustainable food production increases (3).

The global agricultural sector faces a crisis of aging farmers. In many developed countries, the average farmer is over 50, with fewer young people entering the field. In the U.S., the average farmer was 57.5 years old in 2017 (4). Europe and Japan show similar trends, with Japan seeing a sharp decline in young farmers (5). Vertical farming attracts younger, tech-savvy individuals through automation and innovation, making farming more accessible for urban populations.

As urbanization rises—over 55% of the world now lives in cities, projected to hit 68% by 2050 (6)—the demand for locally grown food increases. Traditional agriculture struggles with land limitations and long supply chains. Vertical farming, by growing crops in cities, reduces the distance food travels, addressing these challenges (7).

Climate change disrupts traditional farming through rising temperatures, unpredictable weather, and extreme events (8). Vertical farming, in controlled environments, is more resilient, using up to 95% less water and fewer pesticides, contributing to future food security and sustainability (9, 10).

Vertical farming's key advantage is year-round crop production. Unlike traditional farming, limited by seasons and weather, vertical farms use controlled environments to regulate temperature, humidity, and light, ensuring a constant supply of fresh produce (11). This control boosts yields and crop quality, making it a reliable food source year-round (12).

Vertical farming addresses urban food security by producing food locally, cutting long-distance transport, and minimizing waste (13). In areas prone to climate instability or with limited arable land, vertical farms offer a stable food supply and reduce import dependence (14). They’re also more resilient to climate disruptions like storms, droughts, temperature shifts and pests (15).

Vertical farming fits well in urban areas, using space efficiently and retrofitting buildings like rooftops or basements (16), in addition, it cuts the transport carbon footprint by growing food near consumers, supporting urban sustainability (17). This proximity to consumers results in fresher, more nutritious food with fewer food miles.

An indoor farm is a combination of key subsystems divided in well defined areas suitable to allow the completion of the optimal grow cycles for the crops. The goal of the design is to provide suitable growth conditions while maximizing the space use efficiency and decreasing labor time and requirements. In the image below (fig 1.), the main areas of a typical indoor farm are shown. The site should be designed in such a way that the different material flows are separated, thus decreasing the risk of cross contamination of the final product. A way to decrease the risk of contamination is to minimize human contact with the crop itself; this is an important benefit of automation.

Figure 1. Typical distribution of an indoor farming project

The biosecure areas should be equipped with clean mats and disinfecting stations for the people working in the production. The most important consideration in these areas is the proper disinfection of the operators.

The next compartment in the building should be designated to the seeding and preparation areas. Here is where the raw materials such as seeds, seedling trays and substrate should enter the process. The main considerations in this stage of the process should be a homogenous seeding distribution in the growth unit, hygiene of the raw materials and optimal humidity and temperature conditions of the substrate during preparation.

The germination process is when the plant initially grows from the seed. In natural conditions, this usually occurs under soil. The main purpose of the germination area is to artificially emulate those conditions to stimulate optimal germination.

As the germination area, the growing area should be insulated and separated from the rest to ensure proper climatic conditions. The growing areas are equipped with irrigation systems to provide adequate nutrition, illumination systems to provide optimal lighting and ventilation systems to allow homogeneous climatic conditions.

Typically, the climate control system is designed to perform 3 processes: cooling due to the heat produced by the lighting system and equipment, dehumidification due to the transpiration produced by the crop and ventilation to avoid heterogeneous air conditioning. The irrigation system should provide optimal nutrition to the plants, and is typically monitored and controlled via two parameters: Electric conductivity and pH. Maintaining these parameters under optimal levels will decrease the risk of suboptimal yields.

When the plant is ready for harvest, the grow units should be moved to the harvest area. The typical post-harvest process line comprises weighting, packing and labeling of the final product. To prevent foreign material in the final package, a metal detector or x-ray machine is included in the quality control. To reduce the respiration of the product and quality loss, the harvest areas should be kept under low temperatures and should be well illuminated to allow a proper assessment of the quality of the product. The ready to shipped product should be kept at low temperatures in cold storage.

According to Kozai et al 2020 (18); typical concerns revolving around an indoor farming project are unprofitability and response of the market to the product.

Unprofitability in vertical farming is linked to high initial and production costs, including electricity, water, land, and labor. However, the cost per square meter for indoor projects has decreased over the past decade due to new technology providers, better understanding of production needs, and reduced knowledge gaps.

A well-designed indoor farm should use operational resources efficiently and develop a strong marketing strategy to sell products at competitive prices. Electricity typically accounts for 25-45% of production costs, but this can be reduced by using advanced LEDs, improving lighting systems, optimizing light quality, and controlling temperature, CO2, nutrient solutions, and humidity. Automation significantly cuts labor costs, especially in logistics and post-harvest tasks. Robotics, remote sensing, image processing, intelligent robot hands, cloud computing, big data analysis, and 3-D modeling enhance efficiency, though they require skilled workers, whose scarcity can be a limitation.

Consumer preferences are influenced by various factors, including culture, personal history, health conditions, and brand image. While field-grown vegetables are often preferred, there is growing interest in understanding the origin, production conditions, and safety of fresh produce. Indoor farming’s sustainability and local production appeal can be leveraged.

In general, the taste and nutrition of fresh products are affected by plant genetics and physical, chemical and environmental factors encountered by the plant during its growth cycle. Based on this and the high level of control of these factors found in indoor production, it should be easier to control taste and nutrition. There are several ongoing studies on the effects of different factors on the quality of the fresh products, a benefit of indoor farming is the possibility of performing highly controlled and monitored trials year around and particularly, in high number of repetitions for short cycled products (baby leafy greens).

Indoor farming systems are the newest technology category when it comes to totally controlled environment agriculture systems.

It can be assumed that improvements in LEDs will lead to lower capital and operational costs for vertical farms. The technology categories that will impact long-term indoor farm improvement include:

• Improved LED efficiency
• Improved cultivars that yield more, are more resistant to diseases and transpire less.
• Intelligent data management systems
• Improved dehumidification systems
• Gene-modified crops for faster growth and lower resource consumption
• Automation and AI-enhanced data systems

For vertical farming to thrive on a large scale, supportive policy and regulation frameworks are essential. Governments can encourage the growth of this industry by offering subsidies, tax incentives, and grants for research and development. Implementing energy-efficient standards and providing access to renewable energy sources can help reduce operational costs, while clear guidelines on food safety and labeling for vertically farmed produce can build consumer trust. Policymakers must also address zoning laws and building regulations to facilitate the integration of vertical farms into urban environments, ensuring they become a viable component of future food systems.

To develop a successful commercial vertical farm, start by clearly defining the purpose of the project. Identifying your objectives helps maintain focus. Begin by analyzing trends in fresh products, how they are distributed, and opportunities in local production, along with understanding the growing conditions. This will help you select the most suitable crops for your project.

Crops like microgreens, leafy greens, medicinal plants, and high-end herbs are ideal for indoor farming due to factors like form, short life cycles, and high commercial value. Some farmers have also had success with tomatoes, lettuce seedlings, ornamentals, and strawberries, though their financial viability is less clear.

It's important to research available equipment options, comparing efficiency, cost, and availability to determine what level of control and output can be achieved and how to integrate these solutions into your farm.

Equally essential is understanding the physical, environmental, and resource requirements needed for optimal production. This information helps you assess capital and operational costs, estimate revenue, and identify key risks.

By gathering and refining this data, you can iterate on your options until you develop a project that aligns with your objectives.

Vertical farming is transforming agriculture by addressing global challenges like food security, climate change, and urbanization. As technology lowers costs and improves efficiency, vertical farming could become a key part of the global food system. Its ability to produce year-round, reduce environmental impact, and integrate into urban areas makes it ideal for densely populated regions where traditional farming struggles. However, tackling high energy use and capital costs will require ongoing innovation and supportive policies.

The future of vertical farming depends on advancements in LED lighting, automation, and plant genetics. Gene-edited crops that grow faster with fewer inputs, alongside intelligent systems for optimized decision-making, will drive the next generation of vertical farms.

Vertical farming is set to play a vital role in solving global food issues and creating resilient, localized food systems. Continued innovation and investment in research and development are essential for the industry to reach its full potential as a sustainable agricultural solution.