Greenhouse lighting

Light is important for all plant development. Without light, leaf-growth, flowers or fruits are out of the question. During summer plants usually receive sufficient natural light. But in spring and autumn they profit from your help, for instance by providing lighting in your greenhouse!

 

LED lighting in the greenhouse

For use in greenhouses all sorts of lamps are available, either large or small, rectangular or square. You may choose between warm, orangey light or bright white light. Your choice will depend on the available space and number of plants. Almost all light boxes are equipped with LED lights, using far less current than conventional lamps and making them a sustainable solution for plant lighting.

Grow lights and their colours

Grow lights for plants in greenhouses are available in all sorts of colours, defined as a number of degrees Kelvin (K). The higher number of degrees K, the brighter that light will be. The different colours determine the light's function.

  • 1500-3000 K is dark orange to red and suitable for flowering plants
  • 3000-3700 K is yellow to neutral, providing photosynthesis, so suitable during the growing phase of your plants
  • 4000 K is neutral white and suitable for normal plant growth

 

Why is light so important to your plants?

Light is important for all plant growth. When lacking sufficient (sun)light, plants tend to wilt and do not flower and set fruit as easily as under sunnier circumstances. Since we never know how often and how long the sun will shine, plants may largely benefit from artificial lighting, particularly in spring and autumn.

Advantages of greenhouse lighting

By using greenhouse lighting in very early spring, which provides sufficient light and warmth, your pre-sown plants can be moved from the windowsill to the greenhouse at the beginning of March. Now your windowsill is free for sowing even more plants! More importantly of course, even on cloudy days your plants receive enough light. Another advantage: ample lighting reduces the risk of moulds and fungi to a bare minimum.

Less moulds and fungi

Sunny days, especially in summer, can cause tropical conditions in your greenhouse. Your plants may happen to like that, but all sorts of diseases, moulds and fungi love damp conditions and high temperatures as well. Lighting somewhat reduces high humidity, thereby decreasing the potential development of moulds and fungi.

 

No lights after dark!

The amount of light plants need vary considerably, but most plants prefer to rest at night, in the dark. Darkness at night truly is essential for most plants, and besides, neighbours may consider bright lights coming from your garden at night rather a nuisance. So if possible restrict lighting to cloudy days, and/or to spring and autumn, when days are short.

Power points

Obviously you need electricity in or near the greenhouse when lighting is desired. Do take care that power points or (preferably) earthed sockets are installed on a spot free from exposure to (dripping) (rain)water. In order to avoid diseases and plagues it is of vital importance to ventilate your greenhouse quite regularly.