Choosing lighting for growing microgreens

Microgreens are an excellent source of vitamins, minerals and antioxidants, and growing them is not difficult at all. However, the quality of microgreens depends to a large extent on the type of lighting you use when growing them. In today’s article, we will advise you on how to choose an LED grow light for microgreens and recommend several proven products from our range.

The basic prerequisite for healthy growth and development of plants is sufficient light. This drives photosynthesis, during which plants convert light into energy. While outdoors we can rely on sunlight, when growing indoors it is often necessary to provide supplementary lighting. This applies both to larger fruiting species, such as tomatoes or chilli peppers, and to microgreens, which have slightly different lighting requirements from other plants.

Microgreens go through several growth stages during the cultivation cycle, and their light requirements change accordingly. It all begins with the germination stage, when seeds absorb water and begin to grow. During germination, seeds do not require light, only a moist and warm environment. Once the seeds have germinated, microgreens move into the growth stage, during which they require bright light. The demands for the amount and intensity of light vary, but in general we can say that microgreens need light in the PAR (photosynthetically active) spectrum with wavelengths of 400–700 nanometres. After several days to weeks, microgreens are ready for harvesting and no longer require additional light; they can be stored in the dark, where their growth stops.

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Choosing suitable lighting for microgreens

Unsuitable or insufficient lighting can easily ruin your plans for juicy and healthy sprouts. Insufficient light intensity will cause the plants to have elongated thin stems and stunted leaves. An unsuitable light spectrum will result in distorted growth, yellowing leaves or even poor flavour of the microgreens.

Light spectrum

The light spectrum is the range of electromagnetic radiation visible to the human eye, and it consists of light of different wavelengths. The visible spectrum is made up of the colours that can be observed in a rainbow: red, orange, yellow, green, blue, indigo and violet. Light with different wavelengths has different energy, with red light having a longer wavelength and lower energy, while violet light has a shorter wavelength and higher energy. In addition to visible light, there is also an invisible part of the spectrum, such as infrared radiation (with longer wavelengths) and ultraviolet radiation (with shorter wavelengths).

The light spectrum emitted by modern grow lights generally corresponds approximately to PAR wavelengths, but the representation of individual colours in the spectrum will vary according to the colour temperature, which is measured in kelvins (K). According to the “temperature” of the light emitted by the grow light, we distinguish which type of plants and growth stage it is suitable for.

• 9000–11000 K (cool white) for germination and rooting cuttings.
• 5600–6500 K (blue) for growth and the vegetative stage.
• 2000-3000 K (red) for flowering, fruit formation and ripening

The ideal spectrum for microgreens is light with a predominance of blue corresponding to 5600-6500 K, which supports rapid growth and at the same time contains enough red light, which is also important for young plants.

Light intensity

Another metric that will affect your choice of lighting for growing microgreens is light intensity. The PPFD (photosynthetic flux density) value indicates how many photosynthetically active photons (in the PAR spectrum) from the light reach the plants. Together with the length of lighting, intensity is a variable that allows us to estimate how much energy the plants receive from light. The optimal light intensity for growing microgreens ranges between 200 and 400 µmol/m²/s, with the recommended lighting period for microgreens being 12-16 hours per day.

In a study conducted by researchers from the University of Florida, microgreens grown under low light intensity (around 50 µmol/m²/s) had lower yield and lower antioxidant activity compared with microgreens grown under high light intensity (200 µmol/m²/s). At the same time, microgreens grown under blue light had higher antioxidant activity than those grown under light with a predominance of red.

Higarden tips for lights for growing microgreens

GENT G-LED grow lights are energy-efficient LED lights specially designed for indoor growing of microgreens. They offer a spectrum optimised for plant growth, especially in the vegetative stage. GENT G-LED lights emit a white-blue spectrum with a colour temperature of 6500 K, which is ideal for growing microgreens or other plants in the early stages of growth.

Would you like to learn more about indoor growing of microgreens and other modern gardening practices? Visit our