Crops
Why Lettuce Dominates Vertical Farms: The Cultivation and Economic Case
The crop you see on store shelves from vertical farms is still, first and foremost, lettuce. This is not a coincidence. Lettuce is a crop that fits the conditions of vertical farming — an equipment-intensive industry — remarkably well.
Its cultivation period is short, its low stature pairs well with multi-tier growing, demand runs year-round, and its price tends to stay at a steady, workable level. When these conditions line up, operators naturally reach for lettuce first.
In this article, I lay out the reasons lettuce became the flagship crop of vertical farms, along with the criteria for thinking about the next crop once you want to move beyond lettuce dependence.
The current state of vertical farms and lettuce cultivation
What defines a vertical farm is its ability to produce on schedule regardless of the weather, by making full use of environmental control technology. Keeping temperature, humidity, and CO2 at levels optimal for plants, and isolating the interior from the outside, also suppresses pest and disease outbreaks.
Lettuce enjoys steady year-round demand as an ingredient for salads and sandwiches, but it is also highly perishable, so quality control requires careful handling. The stable production capability of vertical farms works effectively against this quality-maintenance challenge. The reason so many vertical farms have focused on lettuce cultivation is that lettuce’s growth traits match what vertical farms offer.
Lettuce growth traits that suit vertical farms
Reason 1 — A short cultivation period
Lettuce is an early-maturing vegetable that goes from seeding to harvest in about 30 days. In facilities with large capital investment, keeping the utilization rate high is the key to profitability. A short cultivation cycle makes it easier to achieve a high number of crop turns per year, and it also allows flexible production adjustments in line with demand fluctuations.
Reason 2 — A compact plant form
Lettuce keeps a short stem during vegetative growth, with leaves spreading out flat from the base of the plant into a rosette. Because it is low in stature and can be grown with tight plant spacing, it is an excellent match for multi-tier cultivation on stacked shelves. Making vertical use of a limited cultivation area is an important condition for vertical farms, where building costs are high.
Reason 3 — A steady unit price
The unit price of lettuce is only modestly higher than field-grown produce, not dramatically so. However, when combined with a high number of crop turns per year, a price that covers a vertical farm’s production cost is still achievable.
Lettuce is relatively easy to manage
In addition to its growth traits, the ease of crop management is another practical reason lettuce is chosen. Even if temperature control or nutrient solution concentration drifts slightly, it rarely leads to catastrophic crop failure, and plants grow evenly. Reaching the highest quality or the maximum production efficiency requires a deep knowledge of plant physiology and accumulated know-how, but at the early stage of stabilizing shipment quality, the learning curve is shorter than with other crops. Given that new entrants into vertical farming often come from other industries, this trait has a large influence on crop selection.
Breaking away from lettuce dependence
The situation in which lettuce is the mainstream of vertical farms will likely continue. However, for some time now, growers on the ground have been aware that oversupply of vertical-farm lettuce intensifies price competition in the market. People in the field also instinctively feel that relying solely on lettuce puts a ceiling on business expansion.
Introducing new crops requires both improving cultivation technology and opening up sales channels. Other crops are not necessarily as easy to grow as lettuce, and in many cases the demand outlook is unclear as well. The barrier to entry is higher — but that very difficulty is the source of added value.
Recently, vertical farms for strawberries have also appeared.
Strawberries, melons, and the now-hot “vertical farm × fruit”: a grower-first perspective
Wasabi is also one of the crops drawing attention.
Can wasabi be grown with hydroponics in a vertical farm? Actually, it’s a good fit
Conditions for vegetables suited to vertical farms
Building on the lettuce example, the following criteria emerge for crops suited to vertical farms. A short cultivation period (tied directly to facility utilization and the speed of recouping investment), a compact plant body (space utilization efficiency), a selling price above production cost, steady year-round demand, and room for differentiation through added value such as functional compounds — these are the five key criteria.
Lettuce clears these conditions at a high level. When you search for a new crop, the starting point for judgment is how well a candidate performs against these same criteria.
The outlook for crop diversification
As new entrants increase, the overall production capacity of vertical farms is rising, and competition in the lettuce market may grow still more intense going forward. A realistic direction for differentiation is to establish new staple crops unique to vertical farms. If you can avoid mere commodity competition and open up a niche market with high added value, it improves the revenue structure.
That said, switching to a new crop also carries the risk of upsetting the balance of crop turns and unit price that lettuce provides. If you misjudge the unit price level and number of crop turns required to recover investment costs, you can end up in a situation where losses pile up while the facility keeps running. Crop selection requires analysis that aligns with market research and the farm’s financial model.