The Easiest Crops to Grow in a Vertical Farm
In this article we will discuss the easiest crops to grow in a vertical farm, as well as the most common cultivation strategies used by home, hobby and commercial growers, around the world.
Amid all the hype around the newest and greatest accomplishments in indoor farming and controlled environment agriculture (CEA), attention has also been drawn to the limitations of vertical farms; including cultivar capabilities. A large majority of early adopters have been taking up market share in the local, micro, baby and leafy greens space through their innovative growing methods, media attention and appealing sustainability branding. Although greens and herbs are the most common crops in vertical farming, some novel businesses are growing berries, small vegetables and rare heirloom crops, to satisfy niche markets to great success.
It is natural to say that growing microgreens is the starting point for all urban farmers – considering every plant moves through its ‘micro’ phase on its way to growing as large as the farmer desires. Microgreens are quite simple to start at literally any scale, but home and hobby growers traditionally use 10 to 20 trays or ‘flats’ to seed their batches. It takes anywhere from 1 to 3 days for microgreen seeds to germinate and most harvests happen between 7 and 21 days after germination – depending on the growing conditions. Trays are filled with about an inch of substrate or soil and seeds are sprinkled on top; it is critical for growers to have the appropriate seeding density in order to run a healthy and hearty operation. A majority of microgreen growers use this technique for their microgreen seeding, with varying approaches to their irrigation strategies (overhead vs. flood & drain).
The most common microgreen varieties are: pea shoots, sunflower sprouts, radish, broccoli, kale, basil and arugula; with varying cultivation / sales approaches by growers to best suit their clientele. Since microgreens do not grow very tall, they are commonly grown on tightly spaced racking tiers to maximize yields for small businesses. Once the micros are ready for sale, trays can be given to restaurants or more commonly cut down with scissors or a knife and placed into bags or clamshells for local retail or farmers markets. Microgreens are most frequently grown using a multi-layered or tiered vertical farming approach, and are rarely grown on a horizontal plane, in towers or on wall systems.
Baby Leaf Greens
As mentioned earlier, the most common and arguably the easiest cropping strategy in a commercial vertical farm is the cultivation and harvesting of baby or tiny leaf greens. These crops are the quickest to harvest and can be grown densely, enabling a high throughput to any vertical farming business looking for consistent cash flow. Baby leaf greens are a physiologically descriptive term for leafy green crops that are not fully grown out into their final form; they are commonly used in salads and spring mixes within restaurants and in 5oz boxes on grocery store shelves.
The lifecycle of tiny leaf greens is slightly longer than that of microgreens with harvests typically occurring between 28 and 35 days, depending on the seed and growing conditions. Some growers – especially home growers – use a ‘cut and come again’ strategy to harvest the leaf mass of their plants about an inch from the base, letting the plant continue to regrow for a second and even third harvest before the entire plant should be harvested.
The most common varieties for tiny leaf greens are: kales, spinach, romaine, incised, oakleaf, mizuna, frisee and chard. These crops are relatively easy to manage when it comes to environmental controls and production planning since they remain in the vegetative state, require minimal nutrient inputs and do not stay in a growing environment long enough to really heighten the risk of molds or mildews. Tiny leaf greens have been commercially grown in both multi-tiered and vertical plane farming equipment / systems to great success. In order to produce the ideal final product, farmers will either grow tiny leaf crops as mono-crops and blend them together before packaging, or as a blended seed mix with the appropriate grouping of tastes, colors and textures.
With a bit more patience and slightly different environmental conditions, vertical farms have also become known for producing fresh culinary herbs to great success over the past decade. Some herbs can be grown as tiny leaf crops as garnish for meals, however the majority of vertical farms are growing herbs into full plants sold as cut and packaged goods or as living plants in pots, bags or carrier packaging. When it comes to growing herbs there are two approaches to starting off plants: direct from seed, or from a propagated cutting (restricted to certain cultivars). Herbs require similar environmental conditions to leafy green crops and are typically only grown under vegetative conditions with respect to lighting and nutrient management plans.
The most commonly cultivated herb crops take anywhere from 28 to 65 days depending on the cultivar and seeding or propagation strategy being used. Herbs grow well in all growing system designs and fertigation approaches including grow towers, trays, rafts and channels. Depending on the substrate, surface area and system design, herbs can be grown in varying densities and offer some flexibility to the farmer when it comes to post-harvesting uses because herbs can be dried or turned into value-add products with longer shelf lives than leafy green crops. Common herb crops grown in vertical farms include: basil, cilantro, parsley, dill, chives, mint, oregano and thyme.
Specialty Green Crops
The last crop cluster to be highlighted for its ease of growing in a vertical farming system falls under specialty crops. These cultivars are defined as “novel” as they are not commonly or commercially cultivated in certain regions. Due to their novelty, the difficulty with these cultivars is their yield consistency and success in soilless farming systems; however the required environmental conditions are similar to that of herbs and greens. Some of the easiest specialty green crops to cultivate are: shiso, orach, vegetable amaranth, sorrel and watercress. It is most common to see hobby farmers and small-scale commercial growers targeting these crops for niche restaurant and retail markets. Specialty green crops can take anywhere from 28 to 65 days to achieve a harvest and usually require a grower to have some experience in production planning and leafy green cultivation before expanding into more novel crops.
Final Thoughts on The Easiest Crops to Grow in a Vertical Farm
Overall, it is appropriate to say that green crops remaining in their vegetative stage are easiest to grow in vertical farming systems, due to their simple and consistent environmental and nutrient requirements. The additional benefit is a range of quick-yielding crops that help farmers develop a consistent sales pipeline for their immediate marketplace. Growers with varying market strategies and experience will use different approaches to blend tastes, textures and colors for their customers, using a combination of cultivar and life-stage variation. For those new to vertical farming, the best place to start is with some leafy green seeds such as: bibb lettuce, swiss chard or arugula and watch the plants grow up until you are ready to harvest, eat or sell.