LED lighting Seedlings / Cuttings / Germination

For seedlings and cuttings, I recommend prioritizing horticultural LED lights specifically designed for this phase. They offer an adapted light spectrum, often dominated by blue and a little red, which is essential for good root development and compact growth. LED bars or low-power panels are generally perfect for starting.

The main difference lies in the light spectrum. A classic LED is designed for domestic lighting, with a broad and balanced spectrum for human visual comfort. A horticultural LED light, on the other hand, is optimized for plant photosynthesis, concentrating energy on the most useful wavelengths (primarily blue and red) and excluding those that are less effective. This makes all the difference for your plants' growth.

An LED light for seedlings and germination is used to compensate for the lack of natural light, especially in winter or if you don't have sufficient exposure. It ensures rapid and uniform germination, prevents etiolation (when young shoots stretch excessively in search of light), and promotes robust root development from the start. It's the foundation for a healthy and productive plant.

Generally, for seedlings and cuttings, you don't need very high wattage. I often recommend wattages ranging from 10 to 30 watts per square foot (approximately 0.1 m²). The goal is to provide sufficient light without burning the young shoots. Too intense light could stress the seedlings. It's better to prioritize uniform lighting over the entire surface.

For seedlings and cuttings, I recommend a light cycle of 16 to 18 hours of light per day, followed by 6 to 8 hours of darkness. This rest period is crucial for plants to assimilate energy and develop properly. This is a rhythm I often see yielding excellent results for this delicate phase.

Installation is generally simple. I advise suspending the light above your seedlings or cuttings, ensuring it illuminates the entire surface uniformly. Using adjustable hangers is a plus, as it will allow you to easily adjust the distance as the plants grow. Also, make sure the environment is well-ventilated.

In theory, yes, an ordinary LED bulb will provide light, but in practice, I don't recommend it. The light spectrum is not adapted to the specific needs of plants. You risk getting stretched, weak seedlings, or slow germination. For truly good results, it's better to invest in a dedicated horticultural LED light, as I explain in this article.

The distance is crucial and depends on the power of your light. For seedlings and cuttings, I generally suggest starting with a distance of 15 to 30 cm between the light and the top of the plants. You need to observe carefully: if the plants stretch, move the light slightly closer; if the leaves yellow or appear burned, move it further away. The idea is to find the right balance for optimal growth, as I explain in my guide on indoor seedlings.