For your plant to continue to grow lush and luxuriant, it only needs 2 things: water and light, lots of light. It seems obvious, but the truth is that the quantity and quality of light your plants receive is a major factor in their development, and each species has different light needs. Understanding how light acts on plants can give us a better understanding of how to use this resource to our advantage.
That is why today we will tell you everything you need to know about light and your plants.
why is light so important for plants?
Plants are wonderful beings, capable of making their own food; but to do so they need to undergo a chemical reaction called photosynthesis, which allows them to transform carbon dioxide and water into sugars, which is the food that powers the plant's growth. Sunlight is the energy used to drive this process.
Plant leaves absorb a certain portion of the solar spectrum. This occurs in the leaves, thanks to the presence of chloroplasts, pore-like organs rich in chlorophyll, which in addition to receiving solar radiation, absorb CO2 from the environment to initiate this chemical reaction.
But sunlight behaves in different ways on the plant, depending on other factors.
Sunlight has two fundamental characteristics that can vary and have a different effect on plants: quality and quantity. The quality of the light is related to the colour and the quantity to the intensity. Let's delve a little deeper into these concepts so that you can take advantage of them with your plants.
Colours and quality
The quality of light your plant receives is related to the colours and type of light. This does not mean that you are going to put coloured bulbs on the plant, but it is related to the waves that make up the light beam. Each of these wave frequencies has a particular colour (which you can perceive with your eyes only when the light passes through a prism) and not all of these colours are useful for the plant.
Plants prefer to absorb the yellow, orange, red, blue and violet spectrum of light. They do not need green light at all and therefore reflect it. Most green plants prefer blue and red light. Blue light is responsible for making the photosynthetic process more efficient. It is responsible for the growth of leaves, allowing them to stretch. Red light helps to regulate the flowering process and fruit production.
Amount of light
The amount of light is related to the intensity of the sun's brightness that reaches the leaves. To the extent that light reaches the stomata, the process of photosynthesis will be stimulated which will promote plant growth. Now, although the photosynthetic reaction increases proportionally with the amount of radiation absorbed by the leaves, the point at which the ideal level of energy is obtained to initiate photosynthesis, called the light compensation point, changes according to each plant species. If these conditions are not met, then the plant will not grow. It may survive, but it will not expand or flower. It will stop its natural cycle.
As the amount of light increases, photosynthesis accelerates exponentially until it reaches a maximum point, known as the light saturation point, where the rate of photosynthesis does not increase. This is the perfect moment when the plant is working at its maximum capacity to produce food and continue to grow, completing its full cycle.
indoors or Outdoors: Using light to enhance your plants
Imagine you have a square room in the middle of an open space, with a large full-length glass window. You might think that putting the plant inside the house, behind the glass window, would be the same as putting it right in front but outside; but no, the amount and quality of light it would receive would be completely different.
Outside a plant is receiving unfiltered solar radiation from all angles. There is nothing to stop it. In contrast, inside a room there are dense physical barriers (doors, walls, ceiling, windows) that block almost all directions. In enclosed spaces, light usually comes from a single source: a window or an artificial light bulb. This may or may not be beneficial, depending on the type of plant you purchase.
Types of lighting
Direct light or full sun
This refers to the absence of barriers between solar radiation and the leaves of your plant. Species such as cacti, succulents and palms love this type of lighting, as they must receive at least and hours of direct light per day in order to reach their light compensation point.
Medium light or semi-shade
This type of lighting means that there is something that acts as a diffuser of sunlight. This can be a thin, translucent curtain, glass and other plants. This type of lighting is preferred by tropical plants that grow in the lower jungle or forest, such as monstera or ferns, where they are protected from direct light by taller trees.
There are plants that have evolved to be able to live in environments where light conditions are minimal, so they manage to reach their light compensation point with very little. But you should bear in mind that this does not mean that the plant can do without light completely, it always needs some, even if only indirectly, to be able to grow. Many of these plants can survive, but will not grow unless the ideal spot is achieved.
how do I know the light conditions of my space?
Knowing the light requirements of your plant is more or less straightforward, at Be-Green we provide you with a card with all these characteristics or you can look it up in our plant guide; but to know the lighting of a spot in your home you only need a sheet of paper.
Hold the sheet against the light source (the window, for example) in the middle of the day, when the sun is high up. Place your other hand in front of it, a metre or so away, and check the shadow it casts. If it is a dark, sharp shadow, it is direct light. If the shadow is soft, it is medium light. If you see almost no shadow, it's low light.
Play with these conditions, move your plant around, find the perfect spot for it and let it grow splendidly, getting the light it needs.
Dedicated to creating an army of cacti, succulents, poodles and cats to help me conquer the world. In the little free time I have left, I play, write and dance.