How Vertical Farms Can Reduce ‘Shrinkage’ in Greenhouses
April 29, 2025 
Photo courtesy of Eden Green Technology
Celina Gomez, Ph.D., associate professor of CEA at Purdue University, leads a study that explores how vertical farming systems can improve plant mortality rates, or “shrinkage,” in greenhouse environments. Her students get tissue-culture plants and unrooted cuttings to root indoors, then transfer them to a greenhouse to complete their growing cycle. According to Dr. Gomez, this helps reduce shrinkage compared to operations where plants are grown in greenhouses alone.
“Some plants are slow to root,” she says. “So, we’re putting the plants indoors until they have their roots, which eliminates the issue of mortality that we’re seeing. Then we put them in greenhouses.”
The process of getting a plant to root is also known as the “acclimation phase” in a growth cycle. The faster plants get through this phase, the more benefits growers will see. Dr. Gomez’s students are optimizing environmental conditions for plants to root indoors, determining how much light they should receive and what their ideal vapor pressure deficit (VPD) should be.
For lighting, this means looking at the type of light these plants receive and for how long.
“We’re trying to understand how much is enough for these plants, because they can’t tolerate a whole lot,” she says. “At what point does it need to be increased to get plants into the greenhouse as soon as possible?”
One of Dr. Gomez’s students is researching how VPD affects water loss in tissue-culture plants and unrooted cuttings. The student is exploring the optimal VPD for indoor growing, determining whether mist or increased humidity should be considered before moving a plant to the greenhouse.
“Essentially, the goal is to grow stronger plants that will thrive in a greenhouse,” Dr. Gomez says.
This article is a part of CEAg World’s Industry Report: Vertical Farming. Download the full report here: https://www.ceagworld.com/industry-reports/.