Hydroponic Lettuce Farming: How to Start, Grow, Space and Cost

In this article, we bring you everything you need to know about hydroponic lettuce farming. From how to start it, grow it, how much space you need it, how fast will it grow, the cost of hydroponic lettuce farming and more.

In cultivation in the protected area, new methods are constantly being found that should prevent the consequences of poor soil management. In addition, high yields and healthy and tasty foods should be ensured. One of the innovative techniques of intensive cultivation is the system of growing plants without soil, called hydroponic farming.

There is no crop rotation or soil sterilization. Plants have no contact with diseases and pests from the soil, so less protection is needed. Environmental pollution is also less as the system is closed and excess nutrient solution is collected into the tank.

The benefits of hydroponic farming:

• no crop rotation
• reduced occurrence of pathogens
• less use of plant protection products
• reduced pollution of the environment
• cultivation on areas where there were no conditions for cultivation
• high production intensity
• a high degree of automation
• less work in processing, cultivation, disinfection
• smaller consumption of water and nutrients

What is obtained by hydroponics?

Everything is added in a controlled manner to the needs of the crop and thus consumes less water and nutrients, and plant growth is better and faster. Soil cultivation and human labor costs are reduced. Crops can be grown in areas where cultivation is otherwise restricted due to soil.

How to start hydroponic lettuce farming?

Lettuce is very easy to grow hydroponically, and we bring you everything you need to get started:

• choose good quality lettuce seeds
• a vessel intended for hydroponic cultivation which is filled with clay balls and into which a water level measuring device is fitted. The pot for growing plants in water is in a hydrophone with a liquid nutrient solution
• a device indicating the state of water. It consists of a plastic tube that has a built-in float
• that chose the right nutrient solution
• to place them somewhere near the sun, but not directly on all day sun

Growing hydroponic lettuce

For the purpose of avoiding problems arising after years of intensive growing of lettuce in one production area, such as disturbances in the physical and chemical properties of soil, and the development of diseases that are difficult to control, 30 years ago, the cultivation of crops without soil began in the world. Today, farming without soil means farming in a nutrient solution with a substrate (rock wool, coconut, and more) or without substrate.

Growing lettuce is done in pure nutrient solution by continuous circulation technique of nutrient solution (as required by culture).

Lettuce growing begins with the production of seedlings that are planned according to pre-set deadlines. The production calendar is essential for the overall business given that the price of lettuce in the market varies significantly throughout the year and also the cost of production is not the same in winter and in the summer.

Lettuce plants are developed on polystyrene plates floating on the nutrient solution, and the root mass was placed in the nutrient solution. For plants not to fall out from the holes that penetrate through the openings, polystyrene sheets are placed in plastic mesh cups that keep the plant at the level of the plate. Through plastic cups the root develops freely, the plants are transplanted with them and remain in them until harvest. Lettuce is grown by the hydroponic technique of floating containers in the nutrient solution.

Harvesting, storage, and yield of hydroponic lettuce

As mentioned earlier, harvest dates are strategically planned and set in advance with a sowing calendar, all in order to get a salad as a finished product the moment the market needs are greatest, and therefore when the price is most favorable for placement.

Harvesting salad in hydroponic begins when the salad is over the mass of 250 g (including root), this is achieved 45-50 days after sowing in summer or 90-95 days in the winter.

Salad is stored in a cooling chamber which is controlled by temperature and humidity. The optimal storage temperature for lettuce should be about 40 °F, with a relative humidity of 90%.

The harvesting of the salad was done together with the root, the root being slightly bent and wrapped for easier packaging. A hydroponic salad contains more water, and less dry matter than salad produced in the soil which is not suitable for storage and transport, therefore, this is precisely the reason for packing the salad along with the root which prolongs the time of storage and transport.

There are a number of factors that affect the increase in yield, which is why today more and more manufacturers are opting for a modern hydroponic method of growing vegetables. One reason is the better usability of space because of the smaller distance between plants. Plants grow closer to each other, reducing row spacing and the use of artificial light provide enough light for normal plant development.

Another important reason for the increase in yield is the greater number of production cycles during the year because plants in hydroponics grow faster and production is possible throughout the year.

The next important factor for higher yields than conventional farming is an atmosphere enrichment of the protected area with carbon dioxide. Enriching the atmosphere with carbon dioxide results in the faster growth of lettuce because carbon dioxide from the atmosphere is the only carbon source for plants. Studies conducted in Canada have shown that the enrichment of the atmosphere with carbon dioxide increases plant growth by up to 30-50%.

One of the most important factors for both seed germination and further crop development is temperature. The crops have their optimum temperatures and they vary depending on the stages of plant growth.

Apart from those mentioned factors, an important role in achieving high yields and optimal plant supply occupies an optimal supply of water and nutrients.

In hydroponics, the fertilizer is dissolved in water and in the form of a nutrient solution of the plant adapt it according to their needs as opposed to traditional cultivation in the soil wherein open-air drought or excessive humidity can occur due to weathering to lack of nutrients or to over-absorption and accumulation in lettuce leaves.

It is a bit tricky to know how much fertilizers to add, but there is an application called Smart Hydroponic that calculates the exact needs for each crop.

Diseases, damage caused by various pests and poor weather conditions have a major impact on yield levels, which is minimized in protected hydroponics.

Space needed for hydroponic lettuce farming

Well, unfortunately, you usually need a lot of space if you think about going big, sell it and earn something from it. If you are doing it for your own needs, then not so much.

It all depends on where the growth (system) will take place, available infrastructure, electricity, water, climate. What type of lettuce do you plan to grow. And what type of indoor facility you plan to use. Indoor greenhouse, indoor lighted.

These all are factors that change, sq. m/ft/hectare based on the above parameters.

Cost of hydroponic lettuce farming

Again, as with space, if you want to grow hydroponic lettuce for selling, then you will have large initial costs and the costs of heating, ventilation, and additional lighting. But it will be worth it for you, just look out when to sow it so you can harvest it at the best time (when the price is highest).

But, if you are planning to grow it for your own needs, then you don’t have so much cost. You can use techniques that need less space, put them in sunny spaces so you don’t need so much lightning, you can even grow it indoors or in the house so you would need less heating. As you can see, it would really lower the starting cost of hydroponic lettuce farming.