Photosynthesis explained: plants, light and growth

What is photosynthesis and why is light so important for plants? In this article, we explain how photosynthesis works and how you can optimally support this process with the right lighting.

Photosynthesis is the process by which plants convert light energy into chemical energy. This energy is used to form carbohydrates (sugars), which are essential for the growth and flowering of the plant.

With the help of light, water, and carbon dioxide (CO₂), the plant produces nutrients necessary for healthy development. Without photosynthesis, plant growth is not possible.

🌿 How does photosynthesis work?

During photosynthesis, the plant absorbs light through chlorophyll, the green pigment in leaves and stems. This process takes place in the chloroplasts.

Here, light energy is used to convert water and CO₂ into glucose (sugar) and oxygen (O₂). The glucose serves as an energy source for the plant, while oxygen is released into the environment.

☀️ The importance of light and spectrum

The sun is the main energy source for photosynthesis. Sunlight consists of different types of radiation, each with its own effect on plants.

For plants, the PAR (Photosynthetically Active Radiation) range is particularly important. This includes light with wavelengths between 400 and 700 nanometers.

• Blue light (400 - 500 nm) – stimulates growth and leaf development
• Green light (500 - 600 nm) – is partly reflected but contributes to penetration into the canopy
• Red light (600 - 700 nm) – important for photosynthesis and flowering

👉 Read more about the light spectrum for plants.

🌱 Light and plant development

Photomorphogenesis

Photomorphogenesis determines the shape and structure of the plant. Light influences, among other things, stem length, leaf size, and color.

Photoperiod

The photoperiod is the ratio between light and dark. This has a major influence on the flowering of plants.

Plants respond to day length via the hormone phytochrome. When a plant is in the dark for sufficient hours, this can stimulate flowering.

Phototropism

Phototropism is the movement of plants towards light. Blue light, in particular, plays an important role in this.

💡 Photosynthesis and artificial light

Although sunlight is the ideal light source, photosynthesis can also occur under artificial light. Modern LED grow lights are specially developed to provide the correct light spectrum.

This allows plants to grow and flower optimally indoors as well.

✅ Conclusion

• Photosynthesis converts light into energy for plant growth
• PAR light (400–700 nm) is essential for photosynthesis
• Blue and red light play the most important role
• Light also influences the shape, growth, and flowering of plants
• With LED grow lights, you can optimally support photosynthesis