The high-density tower was launched as the microgreens tower, then reintroduced as the baby-green tower (the most appropriate name) before being renamed as the high-density tower again.
Let us compare the tallest model of the regular tower and the high-density tower:
– Both towers measure 2.9 m
– The regular tower has 13 stackable modular sections and 52 planting ports, while the high-density tower features 25 stackable modular sections and 196 planting ports.
The regular tower requires only 52 rockwool cubes/coco coir pods for every harvest cycle, compared to 196 for the high-density towers.
Depending on the crops, the regular tower must be harvested once every 4 to 6 weeks, while the high-density tower will require 3 to 4 harvests during the same timeframe.
When harvesting crops from the regular towers, the whole plant is pulled out of the tower with its root system. However, harvesting from the high-density towers is much more labor-intensive. Crops are fresh cut approximately every 10 to 12 days when they are 8 to 12 cm (3 to 4 inches) long. The root system, the medium (rockwool or coco coir), and the roots of the plants remain in the tower so that they can grow again.
On average, for every single harvest on the regular towers, 3 harvests will be required for the baby greens during the same timeframe.
Aside from the fact that harvesting a full high-density tower takes five times longer than a regular tower, considering that the crops are fresh cut, they do not feature their root system and are much more perishable than regular crops.
Fresh-cut baby greens need to be washed, dried, and, in most cases, bagged immediately after being harvested for retail purposes. Baby greens’ shelf life is much shorter than that of regular crops harvested with the complete integrity of their root systems.
The baby green tower is a fine piece of equipment for hotels, restaurants, etc., wanting to grow baby greens for their use: Crops get harvested and consumed right away, avoiding the bagging process.
Last but not least, the regular towers feature only 13 stackable sections vs. 25 for the high-density towers, making a huge difference in the labor involved in washing the towers.
It is also important to consider that, depending on crop variety, high-density towers require 30 to 50% more seeds than regular towers.
On average, over a 30-day period, when in favorable conditions (i.e., climate-controlled greenhouse), the crop yield of a regular 2.9 m tower is about 10 kg of leafy greens, while the high-density tower may produce 5 to 6 kg.
We realize that 5 to 6 kg of fresh baby greens retail for more than 10 kg of regular crops, but is it worth the investment? The high-density tower will require 4X planting medium, 4X labor for the seedling, planting, and cleaning process, 12X for harvesting, plus washing, drying, weighing, and bagging the crops…
Given that crops have a short shelf life and need to be consumed immediately, Tower Farmers using high-density towers have often reported losses due to their crops not being sold immediately.
Please note that in our experience, and as reported extensively by our Tower Farm customers worldwide, the quality of the crops in the second and third harvests on a high-density tower is inferior to that in the first harvest.
This is why we recommend using the regular towers regardless of their size when starting a Tower Farm.