Everything You Need to Know About Hydroponic Romaine Lettuce

If you’re considering starting a hydroponic farm for your commercial growing needs, you may be wondering which crops to select. Romaine lettuce is a popular choice for a variety of reasons. It’s healthy and commonly used in restaurants and home recipes. It also adapts easily to a hydroponic micro-climate system. 

Romaine Lettuce Recall

You’ve probably heard the news about romaine lettuce recall situations that seem to occur over and over in the US and abroad. There have been four large-scale recalls in the US since 2017 — more than most fruits and veggies over the same period. Some may wonder if this is because romaine is particularly susceptible to contamination compared with other leafy greens and lettuces. 

The good news is that romaine isn’t actually any riskier to grow than other types of lettuce. Rather than susceptibility, popularity is to blame here. Romaine is one of the most common lettuce varieties used in the US since it’s a favorite in salads and sandwiches. More romaine being grown and distributed means more chances of a recall.

On the other hand, lettuces, in general, can be more easily contaminated when grown using traditional farming methods. Problems occur more frequently because lettuces grow low to the ground, where they can come in contact with all sorts of bacteria, pollution, and other contaminants. 

Fortunately, this issue is resolved by one of the key vertical farming advantages. Vertically grown hydroponic plants grow in controlled environments where contamination is far less likely to occur. Vertical growing means reduced exposure to potentially contaminated runoff and other sources of impurities. This means that hydroponic growing is the perfect answer to the romaine lettuce recall problem. And since this leafy green is so popular, it’s an excellent choice for commercial hydroponic farming.

Attribute Details
Botanical Name Lactuca sativa var. longifolia
Common Name Romaine Lettuce (also known as Cos Lettuce)
Plant Type Annual
Size Typically grows to a height of 8 to 12 inches (20 to 30 cm)
Sun Exposure Full sun to partial shade
Bloom Time Late spring to early summer (if allowed to bloom)
Native Area The Mediterranean region

How to Grow Romaine Lettuce

If you’ve decided to start commercially growing hydroponic romaine lettuce, congratulations — you’ve chosen one of the best and easiest crops for your hydroponic farm. The truth is, compared to many options, romaine lettuce is incredibly easy to grow and requires little maintenance. 

The biggest problem that some growers face is the size of the lettuce at maturity, but proper planning can completely alleviate the space issue. If you’re growing in trays, simply make sure you’ve spaced your plants apart enough to allow them to reach their maximum size without overcrowding. These space issues are typically not a problem for those growing in tower systems like ours. 

Since hydroponic plants can grow independently of traditional planting seasons, this is a perfect crop for year-round use. Plant your greens at three-week intervals to ensure you always have some plants that are ready to harvest. 

Optimal Growing Conditions for Romaine Lettuce 

There are a few conditions you will need to monitor to ensure your romaine lettuce reaches optimal growth and health. The ideal water temperature should be between 20–25°C or 68–77°F. Aim for a slightly acidic pH in the 5.8–6.4 range. 

The most common problem with hydroponic lettuces is tip burn. If the edges of your romaine lettuce leaves turn brown or black, the roots of your plants may not be getting enough water. Raise the water level to ensure proper hydration. The roots of romaine lettuce should be consistently moist.

Romaine Lettuce Nutrition Facts

Romaine lettuce is an incredibly popular choice for salads because it is abundant in vitamins and minerals and low in calories and carbohydrates. A cup of lettuce leaves typically contains about one to two grams of carbs and about eight calories. This low caloric load comes with essential nutrients such as fiber, vitamins A, C, and K, calcium, folate, phosphorus, magnesium, and even potassium. 

Romaine is often enjoyed raw in salads or as lettuce wraps. The large firm leaves are a favorite substitute for bread in keto or low-carb diets. Are you looking for a warmer option? Cut your romaine in half, brush with olive oil, and grill your romaine for a tasty and healthy treat. 

To learn more about vertical farming of romaine and other lettuce types, as well as other hydroponic crops, visit Eden Green Technology today.


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