Written by Spirekassen 20 Dec 2023 13:53

The Use of Shading Blinds in Winter

Christmas is here, and shortly, a new year begins. In Denmark, daylight hours have decreased by 10 hours since the summer solstice in June. This Friday, the 22nd, marks the winter solstice, signalling the beginning of lighter days and the start of a new greenhouse year. The upcoming months will be cold, with sparse sunlight and predominantly grey weather.

This article may be unlike any you've read before. We're suggesting the use of greenhouse shading blinds during winter, not just in summer. Consider using shading blinds in your unheated greenhouse during winter nights—it's a brilliant way to support your plants.

What You Should Know About Winter Greenhouse Conditions
  • The temperature in the greenhouse is typically lowest right before sunrise due to heat radiation to the sky, which has persisted all night. This radiation peaks just before sunrise.
  • During the night, the air in the greenhouse remains still. Plant temperature tends to be 1-3 degrees lower than the greenhouse air temperature, making plants susceptible to frost damage even without frost in the greenhouse.
  • Clouds or snow on greenhouse glass act as insulation, reducing heat radiation to the sky and preventing temperature drops in the greenhouse and on plants.


Shading Blinds Are a Stroke of Genius

You may have used shading blinds primarily during summer to control greenhouse heat and protect plants from direct sunlight. However, their reverse effect can be beneficial in winter. By lowering your shade curtains before dusk during the winter solstice, you'll retain some heat during the night.



The natural heat radiation towards the open sky is obstructed, and the little warmth generated during the bright daytime hours is retained within the greenhouse. By strategically using the shade curtains in this manner, you can create a temperature 2 to 3 degrees higher inside the greenhouse. This can be crucial for your plants being cultivated during the winter.


Important Note

When raising your blinds, the next day, do it gradually if you're growing plants in the greenhouse. Cold air often accumulates outside the shade curtains and between the blinds and the greenhouse glass. If raised too quickly, this cold air can harm the plants.


Using Shading Blinds during Winter
  • Raise shading blinds during daylight hours when the sun is out.
  • Lower shading blinds before dusk.
  • Gradually raise shading blinds in the morning to prevent cold fallout.


Interesting Facts about Shading Blinds in Commercial Gardening

Professional greenhouse operators use shade curtains extensively for climate control. In summer, these curtains offer shade to regulate temperatures. During winter, they help reduce energy consumption. In larger greenhouses, the curtains are rolled down at night to retain heat. For heated greenhouses, specialized environmental curtains with built-in insulation can reduce heating costs by up to 70% if strategically used.

Some of the photos in this article are a courtesy from the company Flexgardin.