Why are plants green?

Why are Plants Green?

A plant needs sunlight, carbon dioxide, minerals and water to make food for the plant, through the process of photosynthesis. A green substance in plants called chlorophyll traps the energy from the sun needed to make food whilst also giving plants their green colour. Chlorophyll is mostly found in leaves, inside chloroplasts which are the part of a plants cell that is responsible for photosynthesis and can be found in almost every plant on earth.

Sunlight is composed of a spectrum of different wavelength of light, ranging from 400nm (blue/purple light) to 700nm (red/brown light) absorbs light in the red and blue regions of the visible light spectrum. Green light is not absorbed but reflected, making the plant appear green.

The leaf can be thought of as the food factory of a plant. Leaves of plants vary in shape and size, but they are always the part of the plant best suited to capture solar energy. Once the ‘food’ is made in the leaf, it is transported to the other parts of the plant such as the stems, flowers and roots

In the winter, deciduous plants stop producing chlorophyll therefore leaves appear bright yellow and red in colour. However, these are the leaves real colours usually masked by the reflection of green light produced by chlorophyll absorbing red and blue wavelengths for energy.

What role does Magnesium play?

Magnesium is an essential plant nutrient. It has a wide range of key roles in many plant functions with the enzymes in plant cells requiring magnesium to perform properly. Magnesium also plays a big role in the photosynthesis process, as it is a building block of the Chlorophyll molecule, resulting in leaves appearing green.

Magnesium deficiency, like any deficiency, leads to reduction in yield. It also makes the plant more vulnerability to pests and disease and usually older leaves will be affected first. The initial symptoms are pale leaves, which then become yellow between the veins (interveinal chlorosis). In some plants, reddish or purple spots will appear on the leaves.

Circumstances such as, low soil pH, low temperatures, dry soil conditions and high levels of competing elements, such as potassium and calcium reduce the availability of magnesium. Under such environments, magnesium deficiency is more likely.

Magnesium availability is slightly affected by the pH of a soilless growing medium, with availability decreasing as the pH goes down, especially below 5. Magnesium deficiency often is caused by lack of application, but it can be induced if there are high levels of calcium, potassium or sodium in the growing medium.

Magne Cal+ fights and prevents magnesium deficiencies in plants, helping to maintain their lush green colour. The addition of Calcium, Nitrogen and trace elements in this formulation give the correct balance of nutrition to stop magnesium inhibiting their absorbtion.

There are many factors which can affect leaf colour, including Nitrogen deficiency. Most plant fertilisers contain enough Nitrogen as it’s widely available and highly soluble, but environmental factors can stop plants absorbing Nitrogen, including:

 

Over watering in soil and pure coir
Cold root zone (rhizosphere)
Root damage e.g. from transplanting
Very low pH (below 5)

 

Any one of the above will stop plants being able to uptake nitrogen, causing visible nitrogen deficient symptoms. Therefore it’s very important to maintain the right environment for the plant to stay green and stay healthy.