Seedling to Salad in Five Weeks

Each and every day we sow 500 Boston lettuce seeds in rockwool slabs which are then placed on plastic trays in the grow room. Covered with transparent, plastic lids to keep in the humidity, these trays are also covered with a shade screen for the first 24 hours, to cut down light levels during germination.

About a week later, a selection process takes place, where the weakest seedlings are rejected and those that are uniform in size are all kept. After 12 days, the seedlings are transplanted into the greenhouse.

Our plant nutrient company of choice, Advanced Nutrients, makes perfect products for seedling transplantation. In order to avoid the threat of damping off, their first taste of nutrient solution contains Scorpion Juice, which inoculates the seedlings with Systemic Acquired Resistance (SAR). This acts on the immune system of plants the same way that vaccination does on human immune systems.

Especially useful for farmers who grow from seedlings or cuttings, it fights off and prevents not only damping off, but also powdery mildew, molds, fungi, viruses, and tiny, parasitic insects. It keeps our butterhead lettuce free of disease, unsightly blotches, and other symptoms of destructive pathogens.

During transplantation, we also use Jump Start and No Shock, in order to minimize the impact of being moved on the tiny lettuce plants. Advanced Nutrients ran tests and found that Jump Start, used in greenhouses, increased transplant survival rates significantly, while speeding up growth.

No Shock contains Golden Fulvic acid, root stimulators, key nutrients, and immune boosters. It encourages fast root growth and helps seedlings cope with moisture depletion, injury, and microbes that can harm young plants.

The rockwool slabs are separated into individual seedling cells, which are then placed over holes cut in one inch thick polystyrene boards. These are then floated on top of the nutrient solution at the seedling end of our Nutrient Pond. Our goal is to float 400 new healthy seedlings each day.

Initially, the plants are bunched together, 75 plants per square yard, for ten days. Then they are spaced further from each other, 25 plants per square yard. The first polystyrene boards have 55 rectangular spaced holes, one and a quarter inch in diameter. The second stage boards have 18 rectangular holes, one and a half inch in diameter, to allow for the larger root size and better spacing.

Appropriate amounts of Piranha and Tarantula are added to the nutrient solution at this point. These magic products colonize the root systems of our lettuce plants with beneficial fungi and bacteria, respectively. Not only does this help better nutrient absorption, but it also makes for faster growth and healthier lettuce plants.

Last week I mentioned that we use Piranha as a foliar spray to further inoculate our lettuce plants against many pathogens. My partner and I figure that by using a number of different inoculants, we are sure to prevent the entire gamut of bad microbes that plague greenhouses the world over.

Every day our almost fully automated system takes multiple measurements, such as light intensity, temperature and humidity, CO2 saturation, CF or Conductivity Factor of the dissolved salts and nutrients, and of course, the pH, or acid-alkaline balance of our overall nutrient solution.

If this last balance goes off quilter, the system quickly injects the appropriate amount of pH Up and pH Down, which are scientifically the best products to correct any imbalance in this area. Certain vegetables are especially sensitive to acid-alkaline conditions, and lettuce is no exception.

After seeding, our butterhead lettuce crop takes 36 days to reach the final harvest size of 5.3 ounces or 150g. We used to produce 350 heads of lettuce per day, now we’re boosting production up to 400 heads a day. To do any more than that we would have to increase the size of our Nutrient Pond, which is not economically feasible at this point in time.

Adding Iguana Juice Grow and Bloom to the nutrient mix is having a noticeable, beneficial effect. Our heads of lettuce are more robust and crisp. We ensure that they are free of powdery mildew and other harmful organisms by adding the products mentioned above, but also Protector and Barricade. The first one knocks out powdery mildew, while Barricade establishes further immunity from the inside out.

As a final touch, Sweet Leaf ensures the fine, butterhead taste that our customers have learned to expect. We started boosting production about ten days ago, so we should reap our first increased harvest in about three weeks time.