Here’s an 11-point list of what happens when the pendulum swings from too bright to too dark in a greenhouse. Growers know that successful production is a matter of the right amount of inputs, but many of these depend on achieving the right balance of light to start with. Taken from our guide The magic of getting light balance just right, this list summarizes the impacts of too little and too much light. If you’d like to learn more, we flesh out each point in the free download.
Poor root development
Overheating of the plant cells leads to hydric stress, resulting in poor root development.
Reduced photosynthesis
On either side of the appropriate light intensity, energy is diverted from photosynthesis to maintenance functions such as cooling.
Leaf discoloration
A deficit in photosynthesis, root growth and nutrients increases the risk of leaf discoloration.
Burning
Direct light landing on the top of the canopy creates a risk that these leaves will burn.
Flower abortion
When the plant must prioritize evaporative cooling, it diverts both water and nutrients from building flowers and fruit.
Uses water to cool not grow
When plant temperature is high over an extended period, water is simply diverted from vegetables, fruits and flower buds.
Smaller plants
Under low light conditions, new growth receives fewer inputs.
Lower production
Uneven or low light leads to uneven and low overall production.
Lacks energy to mobilize nutrients
Moving specific nutrients such as calcium requires disproportionate energy input.
Fruit structure problems
Calcium not reaching the fruit can lead to blossom end rot and other structural failures.
New growth is nutrient-deficient
The whole plant formation is compromised under light-deficient conditions.
Over the years, through multiple studies and experiments, we’ve found that there are surprising benefits (sometimes so impressive we had to double-check the numbers) to getting light balance right. It turns out that using screens can make even more light available to your crops compared with traditional methods. How can putting up a screen increase useful light to the canopy? And why does the possibility of removing shade at dawn and dusk add up to 30% more total light to the crop?
For an in-depth discussion, read the Svensson guide The magic of getting light balance just right.
When the light is just right.
13 May 2025 | Gerbera
At Honghe Chuangsen’s gerbera greenhouse in Yunnan, double layers of Svensson’s diffuse Harmony screens create softer light and cooler conditions—improving flower quality, protecting petals from harsh radiation, and supporting energy savings across changing seasons.
17 Jul 2024 | Potplants
Pot plant growers Robert and Walter van den Berg left nothing to chance with the recent construction of a 4.3 hectare greenhouse. Only the best systems were good enough and for that reason, the brothers opted for the PARperfect screen solution from Svensson.
03 Apr 2024 | Seedling
“Talk to the professionals and try something new,” he says. “Slowly transition by doing side-by-side trials. Start with just one bay and see how it goes,” he adds. When the Svensson Harmony trial results were in and Michael Vietti realized the hunch had paid off, he decided he didn’t want to keep what he’d learned to himself.
