LED light recipe can enhance rooting of stem cuttings

Uniformity of the plants and predictability of the crop are key factors for successful production of medicinal cannabis. Growing medicinal cannabis therefore requires a high level of control over the production process, which is possible in greenhouses but even more so in indoor farms. LED lighting may be used to control the different developmental stages of the cannabis crop. Wageningen University and Signify have now made the next steps in a research program that aims to control the different developmental and growth processes, such as rooting, canopy establishment, flower induction and formation of secondary metabolites in the inflorescences.

Light to control your crop growth

Often the variability of plants is already present at the start of the crop, which makes crop uniformity challenging. Therefore, certain measures can be taken to minimize the plant differences and grow a uniform crop. LED lighting can help enhance plant uniformity and quality when the right light recipe is applied. A LED light recipe is defined by the light spectrum, intensity, the photoperiod and the timing of that period.

Medicinal cannabis rooting quality under two different light conditions 1

Plant hormones are affected by LED light

Medicinal cannabis is commonly propagated by stem cuttings, which is usually preferred over propagation by seeds because it is a low-cost method and it delivers genetically uniform plants. Auxins and carbohydrates are plant hormones and play a key role in adventitious rooting in cannabis: a critical process in the propagation of stem cuttings. A powder containing synthetic auxins is often applied because it improves rooting and uniformity among plants. When no rooting powders with synthetic auxin can be used, the rooting is rather slow and very variable. Important to know is that auxins and carbohydrates are both affected by LED light. Preliminary results now indicate that the rooting of stem cuttings can be enhanced by using the right light recipe.

Propagation experiment of medicinal cannabis cuttings under different light conditions

The perfect light recipe for rooting

Now, the rooting process of medicinal cannabis is being studied in detail. Cuttings from the tops of the stems are put in pots and placed in rooms with a controlled environment. In a series of experiments, a range of spectra and intensities are tested for their effects on the formation of adventitious roots of cuttings treated with and without auxins. Subsequently, the effects of light are assessed on the development of the cuttings as well as on the morphology of the formed canopy. Thereafter, we investigate the effects of the light regime on flower induction.

Medicinal cannabis rooting quality under two different light conditions 2

In June 2019 Signify and WUR expanded their ongoing research program to determine the effects of Philips LED lighting on compounds and plant characteristics of medicinal cannabis crops. In this unique research project, they develop specific LED lighting recipes for medicinal cannabis based on a fundamental understanding of the influence of light on crops to enhance purity and composition of cannabinoids. In this series of articles Leo Marcelis from Wageningen University explains what the effects of LED lighting are on improved yield, flowering and other plant characteristics.

Leo Marcelis is professor of Horticulture and Product Physiology at Wageningen University

Leo Marcelis is professor of Horticulture and Product Physiology at Wageningen University, The Netherlands. Leo has a vast experience in researching the physiology, growth and product formation of plants in order to improve sustainability and quality of crop production in greenhouses and vertical farms. Plant responses to LED lighting is a focal point of his research.

Share this page

Related articles

Dynamic light recipe provides optimal and uniform propagation of cannabis

Thanks to the new dynamic light recipe from Philips the grower can steer for uniformity during propagation. This is a benefit which will pay off till harvest.

Using intense light for medicinal cannabis cultivation

Light is crucial to increasing cannabis crop yields but intensifying light levels alone won’t increase yields indefinitely.

Why grow with LED?

High sustainable production

Growing your cannabis with the use of LED will generate higher yield per square meter compared to growing with other light sources. The right light optimizes photosynthesis and flower production and improves your numbers. Furthermore it uses the lowest possible energy input with a maximum production per Watt, a minimal use of water and nutrients, and a great working environment.

Raise the quality and predictability of your cannabis crop.

By using LED light, the climate in your greenhouse or sole source facility can be controlled more easily. LED light comes with hardly any heat; thus the climate can be steered more easily. This results in consistent quality with the right composition of compounds; the same quantity year-round to simplify logistical planning and guarantee reliable manufacturing.

By using a dedicated light recipe for cannabis, plant characteristics can be steered. You can steer certain specific compounds meeting your customers requirement and differentiate yourself in the market.

Contact us

Contact certified partners

Philips products are sold through a global network of certified partners. Find partners in your region for more information about Philips LED grow lights.

Contact Philips

What are the best LED grow lights for your situation? We are here to help. Please use our form to submit your request.

Subscribe to newsletter

Keep up to date about Philips LED lighting in horticulture by subscribing to our newsletter.

Join our team

Interested in discovering your recipe for growth and joining our team? Take a look at our career page for more information.


Learn more about LED lighting in horticulture by reading our latest articles and case studies.


IPM- International Plant Fair
Essen, 24-27 January

Fruit Logistica
Berlin, 8-10 February

Indoor Ag-Con
Las Vegas, 27-28 February

We're talking about

How to build a successful vertical farm
Here are a few key lessons learned from city farming expert Roel Janssen on successful vertical farm projects.